This is misleading. It isn't possible to just hit the sell button on a "dominant share" of a coin. The market will likely collapse on the way to the exit which may already accomplish what you wanted to do anyway as a dominant shareholder. It is a criticism of lopsided distribution, not PoS. If distribution were not lopsided, then to achieve a dominant share there was a significant cost associated, and exiting that market will absolutely not be free.

Deride weak subjectivity all you want, but software checkpoints have zero actual cost and very low social and philosophical costs to anyone that isn't beating the PoW drum (which costs billions of actual dollars every year). Transactions will be dramatically cheaper on PoS and that will ultimately decide what people use - at least as an actual currency.