Then it seems to me that you're missing a third option: the bloodbath has been fuelled for years because it benefits some of the players directly or indirectly involved; and there's no greater good that justifies what's happening, only gains of one party or group over the other. Which would mean it's not incompetence and it's not for the greater good either.
The alternative is that we've been too dumb, for years on end, to just stop, or else that we've done it because we made a (huge) mistake initially and are trying to save face, both of which I judge to be somewhat worse.
Iraq may have been more expensive but this is shaping up to be a much bigger strategic blunder, if there's not some really smart hidden agenda driving it. It's certainly a massive humanitarian disaster. I've found it utterly bizarre that in all the partisan bickering this didn't take central stage in the "Obama (and Hillary) aren't fit leaders" narrative, since on the surface the whole thing looks like a gigantic policy disaster on the part of the US—and I feel that way as someone who almost always supports Democrats over Republicans, and protested Iraq II. I don't get how more blame for the situation isn't publicly falling on the US and the Obama administration.