You've misrepresented the conflict as being one-sided, when it's not. There's a real difference of opinion and analysis, and plenty of "ardency" on both sides.
On one side you have people who believe that predatory pricing is an issue and likely also that government regulation is needed to prevent it. On another you have people who believe that markets are so efficient that predatory pricing cannot happen. What do you think I'm missing here? Can you be any more specific than just vaguely saying I'm missing some nuance?
I meant to contrast "ardent free market defenders," i.e., people in the libertarian end of the spectrum, with those concerned about predatory pricing, many of whom would not consider themselves opponents of the free market. "Ardent" is not, in the first place, pejorative.
It is (mildy, granted) pejorative in the description of a participant in a debate, especially when only one party is it.
Search for the truth is about collecting and reviewing evidence. Being passionate (synonym of ardent) about one side (rather than possibly the inquiry itself) is a bad quality.