To "buy into" something means to invest in it- either monetarily or in this case intellectually. Not buying into something is the neutral position. It simply means there's not enough information to decide. Your case is the opposite of buying in- you actively reject. Meaning no disrespect, you're like an investor shorting a stock.

That's a worthwhile distinction in this discussion. You (erroneously) believe that you have sufficient information to judge the matter. So you reject an idea, even though nothing compels you to make the choice. You've taken a 'short' position on the issue- a negative investment in other words.

Ironically, that doesn't mean your position is wrong. I could invest in a stock for all the wrong reasons, and it could still go up.