I posted something about romances in the 'tropes' thread, but thinking more about it here...
What I'd like to see:
PS:T levels of party interaction (breadth and colossal depth) but no outright romance options for main character. Inter- and intra- party romance lines with main character serving as counselor. We'd need at least two relationship counselors to help with the dialogue, though. Hey, it could be therapeutic and terribly enlightening. Not to mention I doubt any other game has tried something like that.
In all seriousness, there are issues in both quantity and quality that can bog down a game depending on how much content is devoted to this type of relationship. Devs risk exclusion if they concentrate on, say, 2 appropriately nuanced romances--orientation, races, age, "alignment" if there's anything like that. Devs risk shoddy quality if they try to cast the net wide enough to cover all the bases, so to speak. Neither are any good, and though I suspect most will favor quality over quantity, I'll add that game players often like to play something 'representative' besides a good ol' creative role-play. Hacks aren't a decent way to address this, either (e.g. changing the main character's sex flag might open a romance option, but all the text is written for the opposite sex--kinda breaks immersion).
Can both be done? Yes, absolutely--I truly believe it's possible with sensitive writers and substantial feedback testing, but this along with all the other game content falls under the project management trilemma: "Quick, cheap, good: pick two."
So thinking about all of that and the realistic limitations placed on software development like this, I keep coming to the conclusion that it's better to leave openings for player imagination on their own terms (maybe mod opportunities) but flesh out a tremendous setting with a goodly number of freaking awesome party members... much like in PS:T.