Fucking while wearing pants

I don't get why the seme wears pants while fucking the uke, like the uke be all naked and the seme be wearing pants. Like I don't wanna make it a big deal since the people who draw yaoi need to cut corners to make the deadline but, like in tiger flower every time they would fuck the seme always has his pants on and I would get absolutely irritated and when the seme takes off his pants am like Woah once in a lifetime miracle I see this dude with no pants on. Like what's y'all opinion on semes wearing pants while fucking the uke??