LOL -- Alito's not the only one. However, although opinionated, he's also normally very polite. To publicly "diss" the future-POTUS and VPOTUS, not once but twice, sounds a little unprofessional for a Justice of the SCOTUS.
I guess I just cannot see Alito doing something like that. IMO, he would have been respectful, just not enthusiastic, and been a contrite rent-a-crowd for the Executive duo. I just can't see pure disrespect and hatred as the answer for Alito's absence from both big D.C. galas ...
He has publicly dissed Biden from the bench-- in one case a few months ago, a lawyer arguing before the Court mentioned the Copyright Act, and Alito joked, "Copyright? Is Senator Biden a defendant?"