However, even early on in a tournament, you won't get callers into a dry side pot unless they have a huge hand or a good draw. Since there's an all in and at least 2 callers, the pot itself is already pretty big, and unless you have a monster, you aren't going to want to bet enough to take away the equity of someone calling with a draw. Therefore, if you are betting w/o a huge hand, then you'll either be giving someone equity to call with a draw or you'll get called by a huge hand. In the long run, neither of these are profitable plays. As a result, the only bet that makes sense no matter what hand you have is a huge bet that takes away the equity of someone with a good draw (keep in mind, this has to be calculated for the entire pot) and the only hand you'd want to make such a bet with is the stone cold nuts.
I'll grant that you're usually only getting called by good
hands when you bet into a dry side pot.
The question is though, how often is the villain holding a hand that's good enough to call?
I suggest that it's not very often, and you fold out
massive portions of your opponent's range even with small bets. Thanks to the myth that only the nuts or near to it can bet into a dry side pot, your opponents typically give you credit for at least a TPTK type hand, and fold a lot of lesser hands.
The proof is in the existence of threads just like this one. If people called with draws or medium pairs more often, we wouldn't be having this discussion.
Anyway - long story short, there's not nescessarily anything
wrong with checking these hands down. I'm certainly not suggesting we should be bluffing every single dry side pot: often, it really is in our best interests to check down and maximise the chances of the all in player getting busted.
But "always" is a very dangerous word to be using in poker.