I will never understand why people object to sex scenes in Star Trek (or for that matter Star Wars, where they're explicitly banned from ever occurring in the novels.) These books are, at their best, about human nature, life in general, huge moral themes... and the one guarantee you can make is that life will make more life! Sex, and romance, are literally the starting point for all of humanity's existence. Why would you not allow stories to be told about that?
Yes, there are plenty of other places to read about romance and sex, but that's true of anything else in the Star Trek universe too, and I find it difficult to even imagine a realistic character that never falls in love or gets squelchy when the opportunity arises. You may not "want to read about it" but I think that misses the point - in order for stories to make sense, they have to come from characters we believe in and understand, and I don't believe it's possible to do that without including such scenes. It's a fundamental human desire and need - ignore it, and nothing makes sense.
And the show agrees with me. Yes, we didn't get constant soap opera, but even by the end of second season of TNG we had strongly implied sex between Yar and Data, between Riker and at least two women I can think of, and a seriously erotic scene between Worf and his ex.
In the books, the writers don't have the luxury of picking one topic per novel like you can do for each episode; each book must cover larger chunks of narrative space. So in the TV show, you can do an episode just about romance here and there, but in novels you only get a few books to cover each year of time, so there should be romantic elements in each, or at least acknowledgment of the desire.
The Inner Light didn't need sex scenes; it didn't have them. It was also one episode out of an enormous number. If every episode were like The Inner Light, The Inner Light wouldn't be powerful. And the characters need to make sense to begin with in order to do this at all, and denying them romance and sex is just inane.
That said, I didn't actually like T'Ryssa either, and I've said so before, but it's a personality thing with her character specifically. It's not because of the sex scenes in general.