Then the battle is lost, because universities, at least 
  in the USA, are the home of "free speech areas" and not 
  letting people speak who a group disagrees with.

  STEM is often criticized as unwelcoming, but humanities
  has become a place of "agree with me" or be condemned.

It is a mistake to assume that this is a localized phenomenon limited to the United States. Lately - and as somewhat of a testament to how disturbingly uniform and inauthentic, millenial culture has become everywhere - the same kind of intolerance for discordant views can be seen on campuses from Canada to the UK.

I'll leave you with an excellent write up on the topic of this brand of groupthink and shutting down opposing views, on campuses, by Brendan O'Neill in The Spectator :

  Have you met the Stepford students? They’re everywhere. 
  On campuses across the land. Sitting stony-eyed in lecture
  halls or surreptitiously policing beer-fuelled banter in 
  the uni bar. They look like students, dress like students,
  smell like students. But their student brains have been 
  replaced by brains bereft of critical faculties and 
  programmed to conform. To the untrained eye, they seem 
  like your average book-devouring, ideas-discussing, 
  H&M-adorned youth, but anyone who’s spent more than five
  minutes in their company will know that these students are
  far more interested in shutting debate down than opening 
  it up. [1]

[1] Free speech is so last century. Today’s students want the ‘right to be comfortable’

http://www.spectator.co.uk/features/9376232/free-speech-is-s...