It's not like the entire battle system would be automated, just the basic attack. It's kind of a pain, especially for controller users, to have to go back to row 1 space 1 every time they want to use a regular attack. You can't keep your cursor near other skills you may need to use at a moment's notice.

I agree that there are other things they could do to fix it but it's not like auto-attack is going to ruin everything.