Though, you do have a good point. It is sad how conservatives have destroyed the discourse in this country, brought otherwise proud people down to their childish level. I have found myself using those immature insults in the past four years. Just like I have found myself insulting Trump on how often he plays golf. Not because I think they should be effective, but more to reflect conservatives' rhetoric back at them. To try to break through to them so they actually hear what I am saying, to speak THEIR language.
I would be extremely disappointed, and would voice that disappointment, if any of my elected officials or people I am supporting for office engaged in such childish insults and diversions. But, I have not always held myself to the same standard (though, that is one thing that liberals do that conservatives don't understand... they hold their elected and government officials to a HIGHER standard than they hold themselves or the average American, not a lower standard like conservatives show they hold their politicians to). Conservatives are so empowered by the childish insults that Trump and other conservatives (like Purdue) throw around that I throw them back at them because I feel that is the only thing that will carry weight with the conservative psyche (it definitely isn't the things I normally engage in, like facts, or logic, or policy). But just like Trump and conservatives have diminished this country over the past three years through their infantile behavior, I think that liberals are (to significantly lower, but still visible, degree) diminishing themselves by engaging with them in this way.
Ultimately, conservatives know how terrible their representatives are, how much they have sacrificed their ideology, and how much they will be a disappointment to their children and grandchildren in how they have acted. Their only solace is that they have also been able to denigrate liberals as well, bring liberals down a little closer to their level. And, in the zero-sum game of the conservative mindset, it doesn't matter who YOU are as a person. Whether you have morals, skills, or values that YOU find laudable. All that matters is how you compare to EVERYONE ELSE, so making everyone else's life a little worse makes your crappy family and crappy life seem a little bit better.
TLDR... the childish insults aren't worth it. It doesn't accomplish much to convince conservatives, because they can always think of more immature, more childish insults than we can. But, it makes them feel good to have people better than them betray themselves in that way.