Re: Hmmm...
Yeah but that's like saying bananas are rubbish because they go mushy when you stick them up your bum; it's probably true but that's not really what they're *for*.
The high impedance and low power output you mention make them excellent buffers-as an input stage and between stages. They isolate the signal path from what comes before and after them, and tend to be operated around unity where their gain characterics are just fine.
I'm sure people do build gain stages out of them, with shitty results, but that not a shortcoming of op-amps.