We had auto quest completers before BC came out. I remember using it to turn in my timbermaw rep items. There has never been an issue with auto accepting quests via an addon because you still have to click the npc first before the addon took over.

Remember when people ran auction house bots? They stopped that by making the buy auction action protected. If they don't want us auto-completing something, they will make it protected.

Edit:I wouldn't doubt that part of the weekly maintenance is a count of what api functions have been used and frequency of use. They have to know the function is being used.