While I certainly recognise the type of person being described on this thread, and have come across a reasonable number of them, the vas majority of people I know who do gentle/unconditional/positive/whatever you want to call it parenting, are lovely people with lovely, well-adjusted children.
Maybe they're just the ones doing it properly!
I use cloth nappies, and slings pretty much full time, (although I refuse to use the terms 'babywearing', 'clothbumming' or call myself or anyone else a 'mamma') and I've been to a couple of sling meets in my time. Most people have been nice and normal and welcoming. I've had a couple of raised eyebrows over the fact that I don't do the whole UP thing, am prone to shouting and waving my arms about, and use childcare because I returned to work when the DSs where 6 and 9 months respectively, but if people want to be sniffy about that, I just don't engage with them.
I've equally had raised eyebrows over my use of slings and cloth nappies, so there are always people who are going to think their way is the only way. Some people are arses about the whole thing, but then some people are arses about anything you care to mention - they just happen to have chosen parenting to be arsey about.
I think it's also easy to misinterpret people's motives, if their beliefs are very different to yours. Certainly some people will say things that are intended to be snubs/put-downs, but I think others are probably just talking about what they like to do, and not intending it as any reflection on the person they are talking to.
For example, I also know the person referenced upthread from that "hatting" link. She's not a close friend, but she's closer than a mere acquaintance, and she's lovely. Yes, she has very strong beliefs, but she doesn't try to make everyone else fall in line with them, and she'd do anything for anyone who needed help. The word "gentle" is very apt where she is concerned. She'd be horrified to know that anyone thought she was being pushy about any of the things she believes in.