While I understand your concern, and to some extent, sure, you're right that owning your own data does reduce certain attack vectors it's also a trade off that a vast majority of people don't have to worry about either.
But the real important thing to consider is whether the protection you would get from a hosted solution so above and beyond overkill that it matters?
If you're curious why I feel that way, we have written up a white paper on how 1Password Teams (and therefore Families and now Individuals) stores and secures your data.
https://1password.com/files/1Password%20for%20Teams%20White%...
We designed 1Password so that we cannot know anything about your data. We also designed it knowing full well that our servers would be a target. So, we designed it in such a way that if a malicious person were to acquire your data there's more or less nothing they can do to acquire the decrypted data.
What we settled on is having two secrets. Both of which are not known by us. The first is your Master Password, something that you're likely well aware of having used 1Password already. The second part is an Account Key, which is a random 128-bit key generated locally. These two things are never given to us and should never be shared. They are both used for the cryptographic functions in 1Password. Without them both, you can't see the decrypted data.
This is unique in that it actually protects weak master passwords. That's the big deal to worry about if our database of user data is compromised. The first attack is to start running password cracking tools against it to try to find the weak passwords. Except in this case, there are no weak passwords because even if your master password is "a" the attacker still needs your Account Key, which looks something like this:
A3-Z4JZ6V-P9BALK-S6J69-FAXCN-LTDY8-T3QHJ
So, now a password cracker is going to have to guess all those combinations of weak passwords against something much much stronger as well. I wish them luck because the math more or less makes this impossible if a user uses a strong master password as well.
There's some math in the white paper if you're curious about more.
Knowing how it works and how extremely unlikely it is that I am such a target that someone is going to literally spend millions upon millions of dollars trying to crack my account (and still likely get nowhere)... I'm small fish, it just isn't worth it to even try.
Either way, for the sake of learning (I love learning, so I always assume others do as well), I would recommend reading the white paper, if not only to gain some new knowledge that you may not have been exposed to previously. If you have, awesome!
As always, if you have questions let me know!
Kyle
AgileBits