I think many of Solas' criticisms are heavily colored by the disappointment he feels, both in the world and in himself. It is far easier to be negative about others when you are angry at yourself for your own poor decisions. I suspect that, if he survives what ever he is planning to do and things work out, that his viewpoint will also be colored by that success. Coloring the world through your own success or failure is a very "human" or in this case "Elvhen" thing to do.
AND, back to crackpot theories - I'm sure someone has said this somewhere in this monster of a thread I can't keep up with but:
Fact: Solas' orb allows interaction with and physical entry into the fade
Supposition: the Black City may be Arlathan or a facsimile thereof. The Elvhen pantheon, with or without a number of ancient elves may be imprisoned and sleeping in the Black City/ Arlathan. Since none are awake there is no one to sit upon the throne. From the evidence we have, Fen'Harel's power even before the fall of Arlathan was even more heavily tied to the realm of spirits than others in his pantheon so it would make sense for him to use that to imprison the other gods in a place where he had power.
Could Solas' plan be to enter the fade and return Arlathan to the physical realm of Thedas? Would this action have an effect on the contamination of lyrium? I'm going with the assumption that red lyrium/blight/darkspawn are all consequences of a viral infection as supported by evidence that lyrium is likely alive and that dragons can wall of blight infection within their own bodies.