Anders wanted to change how mages were treated and how they interacted with the world. Solas wants to destroy the present world to recreate the one he knows. In many ways he is similar to Corypheus, who awoke in a world where everything he knew and believed in was distorted, forgotten and his actions were vilified and demonized. While noble, he is incredible selfish. Elves may not be the same as they were before the Veil, but they have a lives and cultures of their owns, and his actions are solely for his benefit. The lives of many elves are poor it is true, but times change and people change with them. Playing as an Elf PC, while you face discrimination and prejudice you do change how people look and treat you through your actions. Solas wants the world as it was, not how it is now. Anders wasn't stuck in the past, he knows that mages are feared for a reason. History and the Imperium has shown the dangers of unrestricted magic, but the extremely harsh oppression and restrictions against people over events beyond their controls is deplorable. Kirkwall was a melting pot and violence was inevitable, but the fact it was allowed to occur in the first place shows that the Chantry either couldn't or wouldn't interfere to alleviate tensions shows us that the Chantry does not or did not value the lives of mages in the same way as the mundanes. I believe they both think themselves as the necessary evils, willing and capable to do horrible things to make a better world for their respective causes, when the reality and consequences of their choices affect not just the people they claim to represent, but everyone in the world.