“Why is this any different than any Hillel house in a school why is only Chabad the issue here.”
Well, given that Hillel houses are Conservative/Reform I doubt this is a big concern for them.
As for why the OP is asking about Chabad vs other kiruv organizations, it could be just because Chabad is the biggest and more well known name in kiruv, it could be that he’s looking to pick on Chabad, or it could be due to their carpet bombing-style kiruv that seeks to involve mass quantities.