Domain squatters are attempting to get the maximum value for a domain. Ideally, they are specializing in determining what that maxinum value is and thus refusing to sell a valuable domain for less than that price.
This is actually helpful as otherwise some person comes along and buys the domain and makes some crappy website on that domain and it is their pet project so they don't want to sell (or even worse they have no contact info available and the whois is protected).
The domain squatter only cares about selling it for maximum value. They want to facilitate a transaction.
A bunch of people using quality, high value domains for low value or mom and pop businesses is suboptimal too.
The domain squatter is more likely to prevent that and get the domain to the entity that values it the must (ideally).
There is a value to that. This guy's critique makes me think he doesn't understand the value of speculators in a market, which is ironic because he has spent part of his career building trading software and working at investment banks.