He doesnt want but will do anyway, to me there is no difference. If he truly didnt want he could just stop.
Yes. To the countless victims, it won't make a shred of a difference, they'll suffer and die either way. It's easy to declare someone else's death a necessity while holding himself above and apart. "Give me a valid reason not to hurt and kill you" is ... not the mindset of a character inviting sympathy or the desire to redeem him.
And I wish I could feel that, honestly, because I do enjoy a good redemption story and I did like the character I thought he was (flaws aside). I ended Inquisition with Solas at max approval, had him as my go-to mage and member of my A-Team for story missions along with Cass and Cole, thought he was a sometimes rocky but nonetheless true and interesting friend who was moving past his bouts of arrogance and hypocrisy.
... yeah. Not.
Bioware did an amazing job with him for certain, but they almost did it too well. Aside from the "meta-reasons" of having been manipulated to like him via him having been a companion, and of knowing we're supposed to view him as tragic and redeemable, I just can't imagine a reason to not think of him as the monster he claims he isn't.