Why would this unconstitutional law stand when it violates the First Amendment just like the abortion pill requirement does?
Because the mandate was not ruled unconstitutional, unfortunately. The Hobby Lobby case was not decided under the First Amendment, it was decided under the Religious Freedom Restoration Act. With the current court, Hobby Lobby probably would have lost a First Amendment challenge to the mandate (after all, Scalia wrote the majority decision in Employment Division v. Smith, which was the decision Congress was reacting to when it passed RFRA in the first place)
This does suggest what someone else was saying - that they know they are losing the senate so they are pandering to their low information base. i.e. they know this is DOA but want to make the symbolic move. And look at the sentence I quoted. It's offensive on the face of it.