I've seen similar systems implemented on other sites (like the Apple Discussions).
The idea is good (force people to know and tell us their system info), but this kind of feature isn't always helpful or practical, for a few reasons:
- It isn't always necessary
Many questions (especially those that relate to software) don't require system info.
- All of it is never necessary
I've never seen a question that requires background about every single piece of hardware that the asker owns. Unless there was a good way to only include the relevant system info, having it all there would be distracting and confusing ('Wait, is it the MacBook or the iMac that has the problem?')
- It takes up a lot of space
Listing every piece of software and hardware that you own takes up space and adds clutter. There's no reason to take up more space outside of a question's body, especially when system info isn't relevant.
- People forget to update it
In my experience, people are more likely to include current system info if they write it into their question as they're asking. Centralized info (profile-linked) tends to be forgotten about and gets stale.
I don't think that adding system info to the signature is the right path to take.
What I would like to see, though, is another 'reminder' item shown while posting a question that tells people to be sure to include all relevant hardware and software information.
Of course people wouldn't always follow it, but commenting and asking for info is easy, and people generally respond to it.