I'm going to ignore the recent idiocy about how the market does not (and therefore should not) support anyone who is straight, white, and male. Such arguments have been disproved, dismantled, and deconstructed times beyond counting. And Natashina already did it brilliantly. If certain people wish to keep their head in the sand and argue "what about teh menz!?" let them. Men have two potential opposite sex love interests so far, as do women. That's been the standard since Origins. Of the same-sex romances, there are, so far, two for male and two for female. It'll be interesting to see how the final two romances affect that neatly organized balance. Regardless, cries of straight male oppression or exclusion of men and straight male interests are nonsense.
Rant over. Moving on.
Subjective. Cassandra is middle-aged (just as the oldest male companions), and Josephine and Vivienne are likely at least in their early thirties. I don't think any of them is "conventionally attractive" (gods, I hate that expression!). They're some of the least typical female characters you'll find in video games these days, in every sense. And yet is not enough, because they have to fit some arbitrary notion of "fairness".
Criticism is fine. Saying the devs are bigoted for not doing what you want, though, comes across as entitled (not directed at you specifically).
I agree with most of this. While it would be an interesting change if at least one companion was not pretty, because, in general, games like movies love making sure that the heroes are pretty, to say that the women are all young and conventional (and I take conventional to mean skinny, submissive, white, and blond) is wrong. Vivienne are Josephine are only the second and third times we've had a person of color as a companion, after Isabella. That's excellent and not conventional by game industry standards. Cassandra's toned warrior woman look isn't going to appeal to everyone. And not everyone sees Sera as attractive. Personally, I blame the haircut.
Perhaps the women's styles are conventional by DA standards? Females in the DA universe who are companions and romanceable seem to all prefer dark eye shadow and tend to be brown-haired or brunettes, with the exception of Leliana. So, in a way, Sera being a female companion, a potential romance interest, and blond is bucking DA convention.
Lastly, the accusations of them all young and sexually available is a bit unfair, too. Not just because of the age, as Gwydden pointed out, but also because not all the female companions are available for sex and romance, correct? Or has Vivienne been confirmed as a romanceable companion? Other female characters one can meet, such as Leliana and Morrigan, will not be romanceable by the Inquisitor and the former is an advisor. I do get why people say it'd be nice to have one attractive female companion or party member who wasn't romanceable. I'd argue the same about male characters. It'd be an interesting change from the norm for DA games. But, again, since Leliana is a potential companion, then she counts as a woman who's young, though not as young as she used to be, and attractive but also unavailable to the Inquisitor. Vivienne will be too, if she isn't romanceable. We know Varric won't be romanceable, while Solas hasn't been confirmed as a romance yet. So, unless this changes about Solas, they both would count as attractive men the Inquisitor cannot romance. And there are people who don't think the Iron Bull Sexyback is attractive.