I can relate to what you are feeling. Sometimes it hurts my heart so much when I run in mainstream circles (or chat boards) and hear the ignorant comments that people spew about the "benefits" of circ or why it is not so bad. There are times when I feel that people are just convinced and that there is no talking them out of their beliefs.
However, to me it isn't worth giving up because I know that in telling the inactivist side of the story, I may get someone who is pro-circ to re-evaluate something about her beliefs, or I may be able to share important information with someone who is sitting on the fence or doesn't know much about RIC. Maybe you'll even reach a lurker who isn't active in the discussion, but is reading it because she is trying to untangle all the different arguments she is hearing for and against circ.
When I was pregnant with DS, I had NO idea about what RIC entailed, no clue whether or not I should do it. I started learning when I opened a "will you circ your son?" discussion thread on a mainstream pregnancy board I belonged to. Most of the responses were "yes" for the typical reasons, but a few of the "no" responses and the intelligent supporting information led me to search for more information on the inactivist point of view. So if it weren't for inactivist comments on a mainstream board, who knows, maybe I would have done it out of ignorance. I like to think not, but before I knew better, I assumed that pretty much everyone circ'ed and figured that maybe it was no big thing. I'm just so glad that I read the comments and learned the best thing to do for my son!