I really do not get the point of romances in games. I have yet to see one done very well. And yes, that includes Planescape, which for some reason I occasionally see held up as an example of romance done right.
The big issue I have with game romances on a fundamental level is that it's all in the player's head. You never feel like you're interacting with a human being; it's not a two-way street in the same way a real relationship is. While it's absolutely possible to make sexy fan fiction bait and all that stuff, sex is not the same as romance and a relationship. I think you'd have to have a heart of stone to not find at least one BioWare character vaguely attractive or cute (assuming that person were, you know, real), but I don't end up feeling for that character in any way close to how I feel for my girlfriend. A real relationship is being and life, shared with another person; a simulated relationship in a game is itself a game, one where you need to pick options X, Y and Z to reach a goal in the same way I guide Mario over a bunch of platforms.
And then what happens after the fanservice comes and goes? It's over. There's no lasting consequences, your relationship is never tested, nobody in the story ever suggests "hey, let's just forget about this Darkspawn thing and elope." The entire process builds towards the sex scene, that one "romantic" and carnal moment, but the way it's somehow positioned as a reward strikes me as creepy as fuck, like some Skinner box dog treat for pulling the right lever... and frankly, the way it's treated with such reverence, it feels like the people writing it don't even know what a relationship is, and act like getting into the cute girl's pants is the be-all end-all goal (which doesn't surprise me considering, you know, BioWare writers). If the entire construction of your romance is built up out of the desire to achieve a reward in the form of sex, then you're basically reducing your game to pornography. Sex is part of a relationship, not "the point", and while there's arguably no room for more than Hollywood-style romance in Hollywood-style games, I'd much rather see romance be foregone if it can't be done well. Leave it to modders and fiction writers to add that stuff to the game; as it stands it's just a lot of extra effort that ultimately trivialises character interaction for the sake of a mini-game, and could be better spent on other things.
When it comes to gay romances, I think the entire problem with them is that, due to the binary way the player must interact with characters, the game has to be able to figure out what the player wants based on, most likely, a set of dialogue options. When you pick the heart icon in Dragon Age II, you're basically telling the computer "I am gay/straight, give me more of this." Problem is, there's so many potential reasons for players turning down or accepting certain romantic paths - it's not as simple as "I want to fuck you/I don't want to fuck you", and when you tell Anders or whatever that you don't want to lick his lamppost, it's very hard to anticipate the reason or tone the player wants to take, at least not without creating extremely unnatural dialogue. So while there are players who pick X or Y options, and they end up getting the gay/lesbian relationship they want, everyone else has to put up with the game's poor handling of the refusal case.
And of course, since BioWare wants to appease everyone, they make everyone bisexual, which only amplifies and exacerbates the problem because now you have to take into account whether the player is gay or straight, in addition to whether the player wants romance or not, and for what reasons. It's a lot of variables to keep track of, but without exceptionally good writing and scenarios that mask the game's testing, it's pretty much destined for failure.
Honestly, the only time I think I can really deal with game romances is in games where you're working with established player characters with their own lives, personalities, etc., because that way I can empathise without feeling like I'm stepping into the shoes of the player character. I just got done playing through Minerva's Den in BioShock 2 and I ended up being a little moved by it, precisely because the romance I was observing wasn't really *mine*, but another character's. It was done very simply (even cookie-cutter), and certainly not sexual, but it worked because the story wasn't constantly trying to force it on *me*, yet I could still understand the emotions involved without it being mine. There's also The Witcher 2, where I empathise with Geralt and his feelings for Triss; their relationship feels genuine and is written like they share a deep bond, but that they've known each other long enough that they're comfortable being both together and apart. They strike me as quite possibly the most realistic and mature couple in all of gaming which isn't written as an out-and-out cliche (as it's quite clear they both feel their relationship is open), and that's poignant and touching in its own way without trying to make me feel, as the player-construct-ideal envisioned by a designer, like the centre of the universe.