For me there are many different times where folding AK is acceptable:
1. Against a very tight player who has shown lots of strength
2. On the bubble against a bigger on similar sized stack who has made the aggressive move and gone AI first.
3. Any time during the tournament against a similar size stack or bigger provided they are not a maniac with a huge range when they have been the aggressor and gone AI first.
4. I must still have a significant portion of my stack/playable stack if I fold.
5. If it is a large multiway pot and there's a good chance someone has my outs (which is often the case) and I can get away cheaply.
6. If it will cost me a significant portion of my stack to just call (then I'll either fold or jam)
I don't mind getting it in with AK but I would much rather be the aggressor and give them the chance to fold. To me that fold equity make the hand a much higher EV play. I'm not saying I won't call in any of the situations I've listed but in general terms those are the types of situations where I can lay it down.
I was just watching the WSOP
ME last night and one guy calls off AK against QQ at around 70 players. He was shorter stacked and I know QQ is never folding there but he was so happy to get it in and then busto. Remember that before you're just jamming it in there.