Just to weigh in with my two cents.
First, I disagree whole-heartedly that Avatars add nothing that isn't gleaned from posts. I might post formally but my avatar might suggest a more playful side. There's a reason so many forums have avatars, and it's not because people are dying to have pictures next to their text.
That said, I can agree that it's probably not particularly important for a professional site, though I've seen it done. It's probably not worth the oversight time for Adobe personnel though.
Likewise, signatures can lend a little personality or even a shortcut to user information. Options to not display signatures are very common though, so I don't know why this would be an issue. There are a few forums where I have my professional contact information & company affiliation at the bottom of my posts, much as I would an email. Sure, some of that can be found by clicking the user link (assuming there is one), but for signatures that provide useful information like that it can help lend credibility or weight. Sure, you can put useless fluff too, but that's part of the cues that tell you something about the poster, even if it's negative.
I'm more than a little confused about the angst about 'wasted space'. Every page of these forums wasted the the entire 'first view' with the original post, but no one seems to mind. I've never seen a forum that did this, yet I've never had trouble posting on those forums and following the discussion. They also don't stretch to fill the screen -- which can be good or bad. But it feels funny to read about wasting space when I'm looking at a forum that fills less than half my screen. I'm going to assume that the new forums don't assume 640x480 though :)
There are plenty of forums that go beyond stark text that are perfectly functional, and still very pleasant to read despite 'wasting' space on all sorts of things like avatars, post counts or other things. I post on several forums every day as I manage aspects related to my job & hobbies, but frankly I have a lot more trouble reading & following threads on this site than all of the others (which isn't to say I haven't seen some truly awful forums) -- and they 'waste' a lot more on the niceties.
I'm not trying to rag on these forums, they've served well. Especially when I learn they were written by a couple of guys locked in a room -- as a developer, I can appreciate that! 🙂 But honestly, even with all the bells & whistles you find on other forums I don't find this site loads any faster or displays anymore information at a go than the others. Frankly, I find I see less -- lord knows the number of times I'm responded to a thread thinking I'd read it in its entirety only to realize I read posts 12-15 out of 62.