Most people don't wish death on those they disagree with, and it's blatantly offensive to assume that all "rightists" want the death penalty for traitors while the pure left is this benign, forgiving force of good...which is what you seem to imply.
Regardless, the point stands that false charges can be trumped up (That's a proper use of the verb, not a play on words or anything) and will ruin someone in the eyes of much of the public. Look at how Kavanaugh was maligned by allegations that had no credible basis. If such a tame man as he could be subjected to so much vitriol and baseless hatred, can you imagine how unfairly Trump and his family could be treated if the court was even remotely biased?
Like I said, it's a distinct, if unlikely, possibility. If he's covering for his children down the road out of a fatherly concern that they'll be subjected to such unfair abuse then who are we to judge? Parents generally look out for their kids, and will often go to extreme lengths to do so.
