Players opting out of bowl games

The prospect of being the Citrus Bowl Champion is not a reason to risk millions of dollars. Sorry. It's a 3rd tier bowl game. A great reward for those not headed to the NFL as early round picks, but meaningless in the grand scheme of things.

but where does a player draw the line on that type of thinking?
I mean a player needs to preserve their livelihood so why not play conservatively all year to avoid injury?