I have seen a couple of these proposals and I always have one shared thought about all of them: I never understand why people even want to have an easily, memorable phrase instead of that scary hash160 string. When you buy something from an online store you never memorize their payment details, you click a button and are redirected to a payment processor and it automatically fills in the data needed for you to make the payment. And nobody is ever scared of seeing that page. So why making a payment with bitcoin which means either clicking a payment link using BIP21 or scanning a QR code. But that's just my thoughts
Other problem that I see here, is being too limited (I believe the word for it is collision):
With bitcoin everyone who is using it has a unique address and will continue having a unique address for years no matter how many millions of people use it and generate new addresses.
In this proposal what happens when I register name "Foo", then 1000 others after me want to register the same name? "Foo.Bar"? "Foo.2"? "Foo.1000"?
There will always be very limited number of proper names to use before we start getting to hard names area. And the main issue you raised in the beginning will show up again. It will be hard to remember "My.Custom.Foo.Bar.Name.That.Is.Unique.To.Me".
Also the "centralization" and the "address reuse" issues that are already mentioned are not small things to overlook.
Let's say my son is in college and emails me that he needs pizza money. I'd like to reach a point where I can just send a quick transaction to "ebliever.jr" from my wallet rather than having to look up or cross-reference unmemorizable hash strings. The current approach really only works for transactions with businesses that set up expensive and complex front-ends that minimize the complexity to the customer. I'd like a simple solution for non-techies for everyday life, peer-to-peer and without forcing mom-and-pop shops to invest in expensive solutions.
As far as collisions go, that's why a fair amount of my proposal has to deal with registration issues. It's no different than the problems people face with email. Only one person can grab "
Bob@gmail.com". So we each try to come up with an email address that isn't too miserable but hopefully is easier to recognize and remember, while still being unique. (I'm fortunate in that regard - I've done a fair amount of genealogy research, and I'm pretty sure my first name/surname combo is unique in human history.)
Centralization will be a big topic with any project like this, to be sure. But it's a fact of life in many areas, and it's just a matter of working out the best solution with the best checks on abuse or undesirable outcomes.
I think the address re-use issue can be addressed with a smart contract type setup as I noted earlier, though I haven't thought that through in any detail.