I like Solas but he's a god with all the flaws gods tend to have. Hubris, arrogance, rigidity, a singularity of purpose, etc. In many ways he's closer to the spirits he loves than any mortal being and therefore finds it difficult living with the moral and emotional complexities of the present he's woken into.
As Sera says, his head is stuck thousands of years ago. He's still in that Evanuris court enacting his plan to free the elves from the other gods. A slumbering trickster wildcard who awakened to realise that his apocalyptic plan had unintended consequences and so decides to... enact another apocalyptic plan. The goober.
Like all gods he thinks in absolutes, there's no compromise, he puts a lot of importance on himself, and doesn't see the beings of Thedas as particularly real. Instead filtering them through the lens of a society and polytheistic divine melodrama that hasn't existed for over 7'000 years. A lot has changed in Thedas in 7'000 years. He cannot and should not control how culture and society evolve without him. Dalish culture is their own, they've made it their own, the truth of the gods are extraneous because it's always the people that matter and what they make of their beliefs.
He doesn't see it that way though. He sees it as him having screwed up and trying to fix his screw-up. Well, the people of Thedas sure are going to be acquainted with the truth of the Evanuris now, aren't they? As if they didn't have enough to deal with. I look forward to arguing with him inside my head.