I mean, in all honesty, is it? I mean everyone dying aside, would it actually be a better option in the long run?
It is bad only because of the speculated death toll.
If the Veil could be removed slowly or gradually, and the world turned back to its natural state, I think it would be better for everyone. As the Veil existing is not the natural state of the world, there are multitudes of problems with magic users and spirits getting corrupted, and entire races - the dwarves and the elves being unable to reach their full potential. Also, since with enough magic, basically any idiot can destabilize it, the Veil will always be at risk of being destroyed and causing cataclysmic change. Until it is dealt with safely, the world at large will be sitting under another axe (the one that isn't the darkspawn problem).
Even if Solas doesn't succeed, and you kill him/talk him out of it, there is still the matter of Mythal wanting it down to have her revenge on the Evanuris. There are three existing prophecies about the Veil coming down and the Evanuris escaping from prison - one in the Chant of Light, one from Sandal, and one from Eleni Zinovia (Archon Hessarian's mother). It is going to happen and people are going to die - the Canticle of Exaltations even speaks of a great fire burning down Minathrous right before Andraste and the Maker return. It's going to be crazy.
Mythal is pulling the strings (Hawke's strings, the Champion's strings, Solas' strings), and she will find a way with or without Solas (most likely with), just like she'll find a new host (probably Morrigan).