I think that's exactly the point. It wouldn't surprise me at all if we find out that Solas was in an almost-typical "hero has to save the world" situation and the repercussions were almost as bad as failure.
Again, time will tell. I'm not making any predictions.
I think I'm bold enough to predict that this may indeed be a lot about it - that Solas is a hero who took the risks and those risks have terrible consequences. There's no "happily ever after" for him, no "and he rode into the sunset after job well done"; he isn't even given a courtesy to die so other generations have to to deal with problems stemming from his decisions, as much as those decisions may have been necessary or justified at that time.
That in itself is an interesting story to tell and a character to analyze. And as much as Bioware would probably like (we see that everywhere, and I do hope we reach some interesting new heights in DA4) to tell that story through main protagonist, I don't think a considerable part of audience would appreciate it. We generally like to play heroes that win and our decisions to be mostly good, and we can see an evidence for that almost every time it turns out that player's choices have their share of less-than-stellar consequences, even if decisions themselves had to be made.
Anyway - it occurs to me that the thread went so quick and splintered to so many things that I never made it clear why I like Solas.
I like Solas, because I think that in his place I wouldn't be able to hold to reason, compassion and hope that he does, after all he's been through. And I consider myself to be a generally empathetic person who has something of a careful optimism in terms of where humanity goes and wants to believe that people are generally good, so they deserve 2nd, and sometimes even 10th chances.
But I think that - realistically - if I lived that long and went through so many wars, betrayals and circumstances demanding from me to make extreme decisions, only to watch everything burn and realize that the world suffers because of those decisions, as necessary they could have been at a time, and on top of that spend thousands of years alone, alienated and lonely... I'd eventually break so badly there would be no redemption story for me.
That Solas is still able to hold to a faint hope that he says that he's looking forward to his friend proving him wrong - that he can still even make friends or care about people he tried to forsake in his heart in order to carry out the millenia-long plan he's pretty much lost himself in; that he listens and is open to the possibility that he's wrong about everything that he turns around and considers changing or forsaking his mission if you show him just a little bit of understanding and compassion... the question becomes not "why I like Solas" but "how I could not like Solas?".
I simply love such stories - I love stories when a person is beaten down to a point where they almost turn to monsters (because realistically that could happen even to the best of us, depending on circumstances), but there's still a tether that holds them to their humanity thanks to which they have a possibility to turn their life around. That is incredibly optimistic for me.