IMO, this area (all of the caves, not just this room) is way too hard compared to the rest of the map. I even have less difficulty with the escape from "hell". There are too many monsters, not enough reliable cover, and there is hardly any health or armour. The rather limited movement beyond this room doesn't help either.

Does anyone share my opinion, or do I just suck?

It's hard but manageable (though I'll admit it's been a while since I've last played the full map without godmode + fast weapons + infinite ammo; but I don't think the monster placement in that area changed since my last "legit" playthrough).

The idea is to use infight as much as possible. You can get the spiders to do a lot of work for you...

I have no problems with it, although it sounds like I approach this differently to you lot. I clear the first, smaller cave area outside the first door, then camp there as I pick off the Revenants, imps and stuff opposite on the other side of the main cave and deal with the Hell Knights and whatever below me - mostly with the flamethrower and the rifle, all told. I then take the nailgun to the spider mastermind and it's down pretty easy

Admittedly, it's not as hard as I thought it was.

Still, I've edited the area a bit to make it a little more forgiving on easier skill levels. Nothing left to do here.