For me, it's pretty simple.
When I first saw Floris' post, I kind of had the same thoughts as the OP. However, when I actually took a moment to think about it, my mind changed.
The difference to me is... Floris and team are offering xF mods and services overall. They aren't making me sign up on their site, a site I'd never visit again, just to download the mod.
Sites that require me to signup just to download a mod, when I have NO desire to view/partake in their sites comments, will just be a mod that I don't install. It's still their choice to release it (and possibly limit their number of users of their mod), and it's my choice to use it or not.
The mod was made available and they (Floris and team) shouldn't HAVE to come here to support it. Just like they DIDN'T have to come here to release it (but did).
As already mentioned by others, I myself do not like having the one forum to dump everything in, but that will hopefully be "fixed" soon with the Resource Manager, etc.
So, the bottom line is, you get what you paid for. If you download and use a mod for free, you're owed nothing, not support, not even a reply back to a thread you might post about it, NOTHING. Be happy with what you have, and that includes a base xF install with no mods if you don't like people's support methods.