I would consider this a very poor feature.
Well, it's under Advanced for a reason.
Do they have a warning message before executing this deletion?
Right after creating it, there's a warning:
Backup missingWhen entering the wallet, the warning gets bigger:
No backup - no bitcoins! In
order not to lose your bitcoins
when your smartphone is lost
or broken please make a
backup of this address NOW
and keep it in a safe place!It also gives the option to BACKUP NOW or BACKUP LATER.
When deleting the account, it asks:
Do you want to delete account "X" holding n mBTC?
There's an option to:
Only delete the private key and keep as a read-only account
After clicking YES, it gives a big popup with "Are You Sure? This cannot be undone!" and the addresses you're deleting.
However, even if there is a warning, I always do not read them in full unless it's very short and very precise.
That's on you
I've never used this feature, but after checking, it looks
foolproof.
In short: I don't think it's a poor feature at all!