I don't care what anyone say. I LOVE fanservice, 1. but fan service is often only happening to girls. 2. It's not really sexist toward women if both men and women are treated as objects. 
Just saying.
Even just outside of fanservice, 3. there are people in real life like to dress in skimpy or revealing outfits. 4. If it fits with the characters, then I don't see why not. 5. If Bioware is truly progressive then the idea of nude or tight clothing shouldn't be a subject of sexualizing, but just a matter of preference.
1. As a guy... there are tons of fan service that has never happened to me e.g. coop mass effect singleplayer, coop fallout singleplayer and so forth...
2. That's not ... what sexism is... o.O
It is sexist, if you objectify every single man or woman, just because they are men or women.
It's not sexist, to objectify a single man or woman (or any amount thereof), because of eg. subjective beauty, subjective attraction, subjective suggestive clothing and so forth...
3. And call me predjudiced, but I suspect that in the far majority of cases... it is to show off their body rather than their brains. We see very few transparent skull implants. And it's done explicitly to elicit an reaction to their body.
4. I don't mind skimpy outfits or a bare chest or whatever in my game... I just, personally, it has to fit the situation.
Examples:
A: In the messhall, with recruits around? No, inappropriate.
B: In combat, when there are vital organ covering armor available? No, stupid and evolution demands the character deserves to die for it...
C: Going to a bar/disco? Sure, show a little skin folks...
D: Private cabin twosomeness? Go nuts... literally and figuratively...
E: Memorial scene? No, inappropriate...
5. That is not progressive... that is regressive...
Because it allready is a matter of preference and to some it is sexualising and to not accept that is thought policing.