> it doesn't take a lot of scrutiny to scare the crap out of you if you're a major player in some niche industry

This "scare" characterization isn't how anybody thinks in reality. Everything is a cost benefit analysis, the risk that you'll come under FTC scrutiny is going to be a factor weighed against the potential gains of the acquisition. Companies understand their own place in the market relative to their size and dominance, the overwhelming majority of companies know they basically have nothing to fear from the FTC ever.