That's a very good post raz, but the one flaw is that you're simply bunching everyone together based on stakes. You're assuming everyone at 5/10 is going to be crushed by nitting it up. Maybe 80% of the 10nl field will be crushed by such strategy, compared to maybe 45% at 25nl. Well there's nothing wrong with trying to identify the 20% of the 10nl field that is adjusting, and adjust our game accordingly so that maybe we can win money off these people too, and instead of crushing 80% of the field, we're at 90%+.

Adjusting is the key to poker success, even at low stakes. If optimal adjustment is to nit it up, then by all means nit it up. But nit it up for a reason, not just as a standard. Understand why you are playing the way you are playing. Sometimes playing very tight will be the best strategy. But not always. If you are unable to recognise when it is best and when it isn't, then imo you're not ready for higher stakes.