IMO in that case its their own fault. After all they have free will and can use it against their own good if they so choose. Let them get pwned a few times and see if they learn.
If people want to have dumb passwords and download malware, then so be it. You think they can’t do that today with the google play store? Of course they can. Most malware on android comes from the Google play store.
I don't really understand why a well designed sandbox and permissions system doesn't solve the problem.