As far as I can tell, it's mainly a problem for low levels that save up lots of minking cash for a bit of gear, then lose it one way or another. If I lost my Steel Greatsword, I'd shrug it off and make a mental note not to buy any more non-important items for a while to save up a bit more cash.
Been the cause of a lot of IC aggravation for me, but then again my character is in a semi-perpetual state of IC aggravation.
I personally wouldn't go naked to fight them, that's somewhat ridiculous and bordering on OOC. Punching something that dissolves steel is possibly up there on the list of stupidest things you can do, and I'd actually suggest that they get some kind of huge on-hit damage against unarmed things if it weren't for Monks. (Heck, let's just have some Anti-Ooze shuriken drop and we'll be sorted)
Polymorph, summon a creature, use a ranged weapon, cast spells, throw varnishes, and of course run like hell.... There's loads of things you can do.
I vote keep them. I like them being accurate, and I like them presenting a hurdle that you have to cross, and attack them differently. However, the whole 'Go naked and punch the pools of metal-dissolving acid' shouldn't be happening without the person in question taking 20 Acid damage each punch.
Anyone remember this?
http://www.youtube.com/watch?v=KleAd_YdYa4(Probably NSFW and very violent/disturbing, just so ya know)