Materially - look back at the link and quote I posted earlier. People aren't just voting for the president today, they are voting on a whole host of other State ballots, which include electing SC justices, congresspeople, voting on specific provisions, etc. Who is it that you are suggesting should abstain from voting? It's going to be those on the left, or centre left. The Republicans and others on the right are still going to vote. Having Republican-led state governments and legislatures - along with a Republican president who will appoint 2-3 Republican Supreme Court justices during his term - will have a very real effect on people's lives. It will continue what has already been happening in those Republican majority States already (again, see my earlier link for an example).
Again, it's very, very easy to sit back with your impeccable principles and say what all these people should be doing, but it's completely ignoring how they are experiencing these things themselves.