What happens when someone else gets your FULL wallet and all the keys? There are other wallets aside from Core that do have some sort of HD.
OK but what happens when you forget to backup your wallet (it happened, and will still happen, to a lot of people)? Nothing is perfect, but I think you will concur that safely storing a key ONCE AND FOR ALL is much more convenient than periodically repeating a procedure and you much more likely to lose money because of the latter.
I think it depends on the person. It's a case to case thing. I have local backups of my wallet. And those backups have backups too, in another city. And I have backups in another country, just in case the one I'm in disappears.
If I forget, then that's my fault. If people forget, then, that's their fault. If you get hit by a bus, well, it's the bus driver's fault most of the time (but often times, it's really your fault.)
I have several wallets, and each of those wallets have several addresses pre-generated for that wallet. Like a few thousand. They are used for different purposes. They already have backups of course, and I only need to update them maybe once a year, if at all.
The only other wallet application I will use is Armory (and it runs on top of bitcoind / core), but I haven't gotten around to it because it still does not use compressed keys or compressed addresses.
I have the bitcoin android wallet, but that only stores one key. I don't even use it all that often.
Core wallets are small. Like 1 or 2 megabytes for typical ones. The biggest wallet I have is less than 7 megabytes, and RAR compresses it to about 2. You can get several USB flash drives for cheap. You can email them to yourself (encrypted of course).
I've also dealt with alt-coins, and, as habit, I have backups of all of them, even if those coins are dead (or dying.)
Which reminds me, I'll go make a backup right now. And, I just did. Even with 100% redundancy, they total up to 9 megabytes compressed with RAR. I'm going to go now and copy those backups to another partition. Then to another USB drive.
Good habits.
When you hold a non-trivial amount of coins, you tend to be very careful with them. Go buy like a block or two worth now, before it halves to 12.5 BTC next year. Hold that. I'm pretty sure you will quickly develop good habits of backing up your wallets.
As you can tell, I'm not a fan of HD or even D wallets. I may change my mind in the future, as they are almost random looking.
