A quick Google search shows they're run by "Arn Pearson, Executive Director of the Center for Media and Democracy, publisher of SourceWatch, PRWatch, and BanksterUSA".
If you google Arn Pearson (https://muckrack.com/arn-pearson/articles) , he exclusively, and without fail, writes nothing but anti-Republican hit pieces or about how much of a threat the right-wing is. He doesn't seem to have ever found something bad done by a Democrat that might be worth criticizing.
So this seems to be a typical Democrat non-profit where NY trust-fund nepobabies get to hang out for high salaries and lattes and the bi-weekly Republican hit piece, probably funded by similar billionaires as the Republican donations they decry.
Have you actually looked at the rankings? Only 3 colleges that trend conservative are flagged 'Red' for poor free speech. Over 50 liberal colleges are. I'm not saying that's inaccurate, I'm pointing out that this seems to be pretty factual, and non-partisan, despite who the founder may be. Remember that as bad as many colleges are right now with free speech, liberals are generally not banning books. We of a certain age that lean left are horrified by the college free speech culture and hate to see it happen in places where our kids should be hearing many different philosophies and points of view.
It's probably misleading to use nominal figures to compare this, since there's going to almost certainly be a difference in the number of conservative and liberal leaning universities.