I think there is quite the difference between just being open to sexuality and writing bad dialogue of 6 word sentences only made up of the words slut, bitch, cum, and many different words for fucking.
Fo example huniepop has quite provocative dialogue, not very much either, but it can convey most of the heroines character, whereas pussy saga often makes it hard differentiating between the girls, because they all nearly talk the same.
An eastern example for being extremely lewd, but with quality would be kamihime: they have many pretty extreme niche fetishes in there, they actually have really well written dialogue.
in the middle of sex scenes it also becomes pretty vulgar, but still often fits the setting, while the dialogue OP speaks about is usually completely out of place and sounds more like the people have tourette syndrome

as someone else already said, the time, place and amount of "vulgar" speech makes a big difference between it being erotic or making you eye roll.