Writing Groups

Good afternoon, gentle readers!  It's another Monday, which means it's time for another post from yours truly about the writing experience.
Today, we're going to talk about writing groups.
I loathe writing groups.  Honestly, I can't think of anyone who actually likes taking part in them.  At best, people tend to view them as a necessary evil.
Depending on the members, a writing group can be more evil than necessary, at least in my experience.  I've been a member of two groups in my life and both were extremely unsatisfactory experiences.  Mainly because the idea of constructive criticism in these groups was, "You should write more mainstream stuff that people will actually buy."
Um. Excuse me? I didn't come here for a market analysis, thankyouverymuch.  I came here to see if my writing was clear.  Does the story flow?  Are the characters fleshed out?  Did you spot any plot holes?  Does the narrative need to be tighter?
But I didn't get that kind of feedback from the writers groups I belonged to.  It was more like market research, if the demographic I was going for was angst-ridden poets, holier-than-thou church ladies and little tin dictators.
If the above doesn't reveal it clearly, let me say right now that I remain biased against writing groups.  I believe that most of them do more harm than good. That they foster a writer's insecurities instead of strengthening his craft.
Still, I think aspiring writers should join at least one writers group during their life. Firstly, because once you've joined one such group, you'll probably never want to join another.  And, secondly, because the people who make up these groups can provide a hell of a lot of inspiration for horror stories.