My private thoughts about political lesbianism is that political lesbians are likely already lesbians (by orientation) who at some point found a belief system which allowed them to reject heterosexuality and this was so amazing, such a bolt of lightening where mind, body spirit all aligned and made sense not just as an answer to their own selfhood, personal integration and relationships, but to all the injustice in the world and the liberation of women, they want all women to experience the same.
I think it can be hard sometimes for people who find something that makes absolute perfect sense to them to accept that it won't work for everyone.
On the other hand I am not so sure about the rigidity of sexual orientation as some posters on this thread myself. When it comes to the 'biology' argument our close primate cousins the bonobos are all bisexual (although not exclusively lesbians I think) so bisexuality may be fairly natural and normal in our species too. In humans, lots of women really go off sex after a while or have a reduced sex drive and find their male partner's continuing high sex drive oppressive (of course this can occasionally be the other way around) so perhaps a sexual rejection of men at some point is actually 'natural', and it is fairly common for women to passionately fall in love with another woman around the time of the menopause - a sort of orientation 'switch'.
Even though it is not for everyone, I think political lesbianism is an essential pillar of feminism - it may even be feminism's beating heart - the clarity about patriarchy and the passion for women's liberation is unparalleled elsewhere. It pisses me off when people knock it because a few women are a bit over zealous.
As for the having to wear men's clothing malarkey and have short hair - that isn't true. They simply reject the aspects of gendered 'femininity' which are a hassle and pain that men don't have to contend with. They may wear skirts and have long hair, unless they deem them too much of a pain in the arse for whatever reason. They are about rejecting the gender binary not 'crossing over' to male stereotypes.
As for online forums it creates a false kind of hierarchy where moderators have power over members and frequently this overspills in a way that can become controlling and kill the vibe of the whole community. Moderators need to be as neutral as possible to allow a free exchange of ideas to flourish. Perhaps this radfem fb group has had its day? It's better to get out and meet one another in person anyway.