That's actually a slightly tricky question. You see, if a game has a story, then it is absolutely essential that it have a truly good one, well thought through, with characters acting believably for who they are and what situations they are in.
BUT ... There are also games where the story is barely there and the entire thing is just fun. And some of those are awesome.
It all depends on whether the game creator is intending there to be a story that is taken seriously or not. I guess a few examples are in order. I really enjoy 'Harem Hotel', but if anyone is taking that story seriously I'd be amazed, (and probably a little concerned). It is a game of silly situations for pure fun, and as long as it is happy with that, it continues to delight fans who want some silly fun.
I don't think anybody here wants their story to be taken 'seriously'.
What does that even mean? Millions of people love Star Wars but I don't think anybody thinks the Force is real. Sure there are serious debates about the movies but again I doubt anybody thinks the story is real. People who took it seriously ,maybe by attacking actors who play the villains in real life, would be locked up.
I don't think any of the marvel movies as serious and yet they make a lot of money.
My point is of course most hentai games will have silly stories. That's pretty much by design and really on par with most movies. But there is still a big difference between fun well-crafted stories and poorly constructed cliches.
Looking at your example, I love Harem Hotel and I think the story is very good. Do I take it seriously? Well, of course not, it's fiction and it's silly fun, like most Hollywood movies, but I still think it's a good story in the sense that the characters are well constructed and can elicit some emotional response in the player. The overall world also feels unique because of its mix with fatasy.
But games with bland loserville mcs and cookie cutter floozies, mixed with trite dialogue? All set in some nondescript condo or gym that could be anywhere? Nothing interesting there. Pass.