I agree that hirelings are pretty much useless... My first run through I used them, a lot, and my character suffered equipment wise for quite a long time... and I was not able to hunt the dungeons very well as a result. I was also using a ton of potions...
I like the idea of them, but considering the 2 types, completely useless fodder, and somewhat useless fodder... The ROI on them is just not worth the effort when they die, normally, in the first few rooms of a dungeon.
It would also, be nice to see a larger range of them. Rogues - Trap & Ranged, Clerics, Fighters, the full gamut. But when you are level 15, and you have a Fred (Small halfling you use to throw at traps... really old D&D reference from a gaming group I used to be part of) and all they have is leather armor and a short sword... it seems you should have more than 1, or they might come with better equipment for the cost.
My current opinion is, if it is decided to keep them in the game, a complete overhaul of them is probably needed.