There was never any commentary from a writer/dev about avoiding a romance scene with Solas. His writer just wanted that to be left up to the player. Possibly he didn't want people to feel uncomfortable if there was a definite scene and then Solas did his Thing. Or keeping it ambiguous allows asexuals to have a romance and not feel the pressure of a sex scene. I'm glad they left it so either way, because while I'm sure my Lavellan was enjoying side benefits with Solas it didn't feel necessary to the romance. If Solas and another Lavellan just never approached a physically intimate relationship, it wouldn't have lessened the emotional and spiritual impact of the relationship.
*wipes tear* That entire post was beautiful. =')
On the bolded, I was actually just talking about this with a friend the other day. It can feel a little alienating for asexuals that enjoy BioWare/video game romances but resent the forced sex scenes. (Much like in real life. Asexuals make up only an estimated 1% of the population, so the odds of us finding another asexual or demisexual who is romantically compatible in terms of personality, life goals, moral values, personal beliefs, etc. is very low, so we kind of have to turn to the sexual crowd for romantic attachment, which causes guessable frustrations.)
Not for nothing Solas has a sizable asexual fanbase (self included), since here's a romance where asexuals can enjoy fantasizing about a sweet romantic relationship without a mandatory sex scene (*cough* all DA2 romances sans Sebastian), or feel like our characters were eventually pressured to have sex to placate their partner. (Yeah, you can politely turn down Dorian or the DAO companion who invites you into their tent, but they're pretty disappointed, so you know your character will have to give in eventually. While all relationships require compromise, many romantic asexuals deal with it enough in real life they don't necessarily like having to deal with it in their romantic fantasies.)