Possibly because:
1. It not a huge issue, but a minor annoyance, unlike the data connection bug
2. It only affects some phones
3. There might be no easy fix
4. They don't want to advertise a minor annoyance that they can't easily fix
Have you tried the app shown here though:
ATT Nokia Lumia 900 Rattle.mp4 - YouTube
Adjust the vibrate frequency?
1. Minor annoyance, yes. Reason not to promote the phone and get other people to give Win Pho and Nokia a chance, also yes.
2. True, but apparently it's a pretty good number of phones that it affects. Especially among the new batch of white ones. I had a black one that was fine, but EVERY white phone I've put my hands on has had this issue. Also, among the display models in stores, 2 more cyan and one black. In the grand scheme a small number (maybe), but still, that's every phone available within 15 miles of here in the suburbs of a major market (Philly).
3. Also true, this is apparently a hardware problem, short of giving me a new phone without the issue I don't see a fix. But, I do hold out hope for a new phone that works properly. My major concern is that there's obviously something wrong with the camera mechanism. How long will it remain an annoyance and not manifest itself into a major issue is an unknown. But there is something mechanical that is not right inside the phone. I can't see this being a good thing in the long run.
4. Of course they don't but word is spreading pretty fast among the community of early adopters. All of whom are key to the success of this venture. Seeing how so (relatively) few people are giving them a shot here, it's probably in the best interest of the hardware manufacturer to make sure the ones that do are happy and will go out and encourage others to jump on board.
I have used the app and it exacerbates the problem when set at default. Set to a lower intensity setting, the problem is less noticeable, but the app doesn't run all the time (nor would I want it to, I like to have some battery longevity) and I don't believe that it controls the vibration when a call or a message is received.
I'm taking this too seriously, I know. I love the phone, and it's just a small annoyance. But, honestly, I was hoping for a more solid product from Nokia. They're better than this. And the response that I got at 3 AT&T stores (two corporate, one franchise) was horrifying. I've been one of the few that have never had a single issue with AT&T in the 12 years that I've been a customer of theirs so it came as a bit of a shock to me because I'm used to being treated very well by their customer service staff.