I think where people sometimes go wrong in MTTs is not putting enough value on their tournament lives. It's easy to call when the amount is an affordable portion of your stack, but when it's enough to bust or cripple you, I think that has to be factored in, especially considering that in most pot odds
calling situations, you're going to lose the hand the majority of the time.
In addition, pot odds aren't as straightforward when it may be necessary to call multiple streets. So for example, if the flop gives you nine outs to the nut flush and the opponent bets, before you call based on the pot odds at that moment, you should also consider whether the opponent will bet again on the turn after you miss which will happen most of the time.
If he will and you can't call the second bet, then your pot odds are really based on nine outs once, not twice. If you can call it and plan to do so before you call the flop, then the situation involves a combination of pot and implied odds, not just the former.