With iOS's 2FA system : I've had to click buttons on other devices. Enter codes on other devices. Enter codes from other devices. Click links in emails. Type my passcode on other devices. I just ... don't have a grasp on it at all.
That's not good.
With regards to the backup issues outlined in the article, it's hard to say if the backup leak is a major issue.
Take the casual user: They won't be making iTunes backups. Most casual users are probably just doing iCloud backups. In fact, they don't do backups at all; iCloud backups are automatic so they don't think about it (it just works).
Take the security hard user: They'll have a password instead of a passcode on the device. So adversaries probably won't get access anyway. Of course, it's possible they shoulder-skim your password, whereas they probably won't be able to ever shoulder-skim your backup password. So certainly Apple's change here _does_ objectively make the system weaker.
It's hard to say if what Apple did here was the right thing. Like I said, I don't think most casual users are doing iTunes backups, so why even bother making iTunes backups more user friendly?
Regardless, it could certainly be improved. Maybe require 2FA to reset backup password?
The issue where you can reset the iCloud password is certainly troubling. It's a hard issue to balance, as Apple doesn't want to set up a system where the average user gets locked out of their account because they forgot their password. But it really shouldn't be possible to take a single iDevice and password and take over a user's iCloud account.