I am able to earn 0 merit... in my local section.
Local section is a different story. There is much less traffic, and also, you correctly noticed, that merits are always subjective. They are similar to "likes", but just have a more serious name.
All my posts worthless

? ALL ?!? ....
No, it just means, that people are either hoarding merits, or there are not enough sources in a given place.
And casually all people that write "yes thank you" or "yes I agree with you" .... These deserve merits because I have said something useful or something right?
Giving a merit is very similar to writing "+1", "thank you", "I agree", or something similar. Theymos didn't receive a single merit from Satoshi, but when he got "+1", then you can look at it in the same way, as if he would get it.
Because this is the main reason, why the whole merit system was invented. If all posts would have high quality, then that system would never be needed, because the mere presence of a given post would imply, that it is worth reading. And this is the case for example in mailing lists, where everything is strictly moderated. But when you have a forum, where newbies are also invited, then something like merit system is needed, just because newbies don't want to see "your post is waiting for approval" after writing anything.
And also, the presence of "+1", "thank you", or similar posts, instead of merits, is usually a hint, that instead of writing it, merits should be sent. Which is why I think some people should be able to somehow reach negative amounts of merits, which could be filled by those with positive balance. Then, we wouldn't need topics like "link posts to merit sources", but instead, some users could do that from UI directly, and that list of posts could be browsed by sources. Maybe it is a good idea, to have a rank somewhere between "source", and "non-source", where some people would be able to fill that kind of lists (making it open for everyone would be too spammy I guess).
My own definition of giving a merit is "this post is not a spam". I can disagree with someone, and merit that person anyway. Maybe I want to correct someone, who is wrong, by quoting that person, and pointing it out (and also sending a merit, because if something is worth replying to, then it is usually also worth a merit).
And then, it becomes semi-automated: if something is quoted, then it is usually merited (unless blacklisted). And if something is "not a spam", then it can be whitelisted. By using "quotelist - blacklist + whitelist", I can spend many merits, without thinking too much about it (and of course, it is never fully automated, so each merit requires a manual action from me; my tools can only make suggestions, not decisions).
I guess, a more general version of this idea would be to have board/topic based "merit weights".
It is already implemented. You can give any amount from 1 to 50. If you want to split it between WO merits, and non-WO merits, then just send a single merit in one place, and two merits everywhere else.
Not to mention that merit history can be explored by anyone on pages like BPIP, so maybe it is just a matter of adding some rows and columns, when displaying statistics of a given user.
Another idea that I've been rolling around for a while now is to allow 0-merit sends. Sending someone "0" merits could be thought of as sending them a "like" (and, for example, instead of it displaying above a post as "LoyceV (0)", it could appear as "LoyceV (L)" or "LoyceV (+)", or something).
Sending things should have some costs. If that would be implemented, then users would need to provide some Proof of Work, before sending zero merits.
Also, merits should be treated as "likes". It has a serious name, but it is just an anti-spam feature, really.
I wonder if the WO regulars would be very against the idea of their thread being made "like-only"?
I think it is better to link posts to people, who have plenty of merits. And then, they can give just one, if they like the content.
In my view, you shouldn't be able to formulaically rank-up an account by carving a pumpkin, baking a pie, making a shitty pizza, and then repeating agreeable things on the WO.
Merits are always subjective. And I think demerits should be avoided. If you think, that there should be less content, then this is what can be achieved by making moderated threads, where every post would be reviewed by someone, before being published. Some places, like mailing lists, are using that model, the question is: do you want to see it here?
Looking at Bitcointalk now, I don't think I'd join today...
You can always try to reach more moderated places, like
mailing list,
GitHub comments,
Delving Bitcoin, or things like that. They have higher standards than forum, and if you wonder, why developers are no longer as active here, as they were in the past, then I can give you an answer: they just moved somewhere else.
But, if you decide to join different places, then be prepared for your posts being rejected. Or be prepared to wait a few days, to see your content published. It is all normal and healthy: if there are higher requirements, then obviously, there is less content.
Now it feels like some kind of weird third-world school where the passing grade has been lowered over and over and all the "graduates" are idiots
Because it is often the case. There are many things, which I would like to see (and merit), but they are not there yet, because a lot of effort is needed, to make them. And it is yet another reason, why I usually send a single merit, and not "50". Also, receiving a single merit from 10 people is usually worth more in my eyes, than a single person sending 10 merits, because then, there is a bigger circle of people, who need my content, and think I am not a spammer.
As that been discussed for and it has not led to any acceptable resolution (the status quo remains), what can actually be done?
And what is done, when some features for BTC are proposed, and rejected? Well, you make a soft-fork, or a no-fork solution, and then it pushes things one step forward (some people also make
altcoins, but then, they are usually worse than the original version).
Want to see zero merits flying around? Write a plugin for a browser (hint: put some Proof of Work or other protections, to avoid being flooded). Want to separate WO merits from normal merits? Just display them differently, and count them differently in statistics. There are a lot of things, which can be solved by plugins or third party tools like BPIP, if they won't be solved officially, by changing the code on server's side. If server cannot meet your requests, then you have to modify the client, or make another server, which will do, what you want.
Do you think I should make a "WO Explorer" on Talksearch to help with the thread navigation?
Yes, of course, that's the spirit! This is exactly what should be done in practice: less complaining, more coding. Because this is what can really push things forward.