I find a bit of irony in the concept that Fremantle users claiming their OS is "better" is considered non-acceptance. Especially when less than a year ago the hostilities (which you now see as non-acceptance) arose mainly from the same claims in the opposite direction. Though I have to say, I've not really seen anyone making the claim that Fremantle is better than Harmattan.
That's a bit extreme. You're talking about not just a different device, but a totally different mind set. It's like asking how a mini owner would feel showing his car at a monster-truck car show. Sure, it's all cars to an outsider; but the communities are too diverse to co-exist pleasantly, as their mentalities tend to be polar opposites.
You can only expand a group so much before the lack of a unified direction causes disharmony and breaks the community apart. I'm not saying you can never add anything; but throwing the barn doors open and trying to pull in everyone isn't an answer either. (You can do that, but then you turn into Gizmodo.) In order to have a stable community, we need groups/devices will fit well and have similar goals and ideologies to the existing group. Most of the other groups that have been brought up in this thread (Mer/Nemo, Tizen, Spark/Vivaldi, etc) have similar qualities. iPhone does not.
I'm really curious where the un-welcome feeling comes from in the Harmattan camp. Where are you seeing people saying "Harmattan sucks", or looking down on Harmattan in this forum? I don't think anyone here has that attitude; or if they do, they have the same attitude against all the devices in this forum (ie they're trolls).
Most of the "hostility" that gets brought up was not toward Harmattan, but early MeeGo. And as most Harmattan and MeeGo folks will tell you, they are not the same thing at all.
That was frankly caused in part by Nokia, in setting up a separate home for MeeGo and inadvertently amplifying the "us vs them" cycle that commonly happens with hardware shifts. There were smaller waves between the N*00 releases, but it all got ironed out because we shared resources and a very similar code base.
Having a small handful of active MeeGo developers show up in the forums bad mouthing Maemo didn't help. It also didn't help when the same group actively discouraged individuals and vendors from developing for Maemo because it was "a dead end", recruiting them to instead to come over to the new MeeGo home to work on "something with a real future". Nothing causes distrust among communities like one side trying to poison the well.
Even with that rocky history, Maemo and MeeGo are still family, and have slowly started to work together. There are Mer/Nemo threads here on TMO, and active discussions about aiming at setting up unified platforms, both forum-wise and OBS-wise, which I hope to see continued by the next Council.
To be frank: I think a lot of this "we're unwelcome here" talk is (IMHO) based mainly on topics that have been settled and moved past for the most part. The main thing stopping Harmattan users from coming here is Harmattan users, not how forum members react or behave toward them. When formeego.com goes dark (which is happening soon AFAIK), the lights here will be on and a welcome mat will be at the front door. Whether Harmattan users come in and join those already here, or go off to form their own home will be more up to them than anything we do here.