I know a few disgruntled types, but I tend to avoid them. I find those people draining. My thinking is, if you don't like your job, do something about it instead of moaning about it.
I have had similar conversations. Invariably I'm told how they need the job, they have families, bills, blah-blah. That's a reason to not quit today, but if you're that unhappy you should be looking around so that you can leave on your own terms eventually.