Is it because the media tells them to?
I mean, useless shit is fine in moderation, but I'm referring to people who treat the president's sex life as a political issue.
The only potential political ramifications I've heard about this whole thing is that he may have used some of the money from his campaign to pay off Stormy Daniels, which would be a campaign finance violation. I'm not sure if there's evidence of that or not. It's also a sort of phenomenon where people who hate Trump will just go at him for anything these days. I was listening to one of Ben Shapiro's podcasts (not a conservative, but I think he's got relatively high journalistic integrity), and he mentioned how much of the French press was confused when their president came to speak to us and they could not find much coverage in the US news about it. Some thought he didn't speak at all, and some just couldn't find information on it for a bit because everything was about something else about Trump that was pretty minor.
And the other reason you might be concerned is that one possible viewpoint a person can have is that someone who governs over the people should be a moral person if they're going to do that, and that it's a bad idea to have immoral people in that kind of position; I tend to have that viewpoint, which is why I think Trump is gross and I would rather that he isn't our president, but he was duly elected and there's no proof of wrong-doing that is worthy of him being impeached (yet), so this is where we are. Because I don't think he has strong morals at all, and if you want to be president of the United States, you should be a generally moral person - I don't even necessarily have to agree with you completely, just have relatively good convictions and be strong in them.
Probably worth noting my wife is basically the opposite on that point - when one guy who was running for governor of my state (or perhaps a US Senate seat, I forget), was caught banging prostitutes (he's married), the question on local talk radio was whether it mattered for electing him. I say yes, but my wife doesn't care; she said something like "I don't care about your personal life, can you do the job?" So people can have varying opinions on the matter, too.
99% of people are total retards and care about useless shit. Do you know what Lyndsey Lohan looks like right off the top of your head? If yes maybe you're a little too concerned with wasting your time and not enough concerned with making yourself better.