Some revolt... as the commenter said they should just stop using the damn site and leave the third party developers alone.
That fact that they need classic Facebook so much they're willing to become a 'developer' to exploit a profile work-around means they're more addicted to Facebook than the average user.
Not necessarily - pissed-off yet addicted users are often the driving force behind adoption of competitors, should one arise. For example, Y!Mail adopted its redesign about a year after GMail came out, and a lot of my friends that had been loyal Y!Mail users (and GMail holdouts) switched because Yahoo was taking away their UI anyway. Most of the modern Harry Potter fandom sites (FictionAlley, SugarQuill, GryffindorTower) were created because Fanfiction.net abolished their forums. The final nail in classic Netscape's coffin may've been that they changed their UI for Netscape 6, so that IE5.5 was more like classic Netscape than the new Netscape was.
The difference is: name a web site that could POSSIBLY work as a replacement to Facebook.
New Facebook is still fast. It's incredibly effective. It's just new, and as such takes some getting used to. Once the change is done, people will adapt. And the reason they will? Because no other web site has TRIED making a platform as powerful as Facebook's. Not even Bebo or Virb come close.
Exactly, these are hooked users. Casual users might not even noticed the change, or if they did, think nothing of it. Then there is a large category of people (myself included) who think the changes are a huge improvement. It's amazing how much resistance even the smallest change faces.
I used to run a fairly large social networking site (before it was called a social network) with forums, photo galleries etc. and had a similar experience. We changed the design fairly drastically and there was mass revolt.
Two competing sites were started that were similar to our previous design. For weeks it was all anyone talked about. People left, they said they'd never come back and they joined the other sites.
After a month or two people started coming back. They started to see the merits of the new design and features. After 3 or 4 months it was if nothing had ever happened. The competing sites fizzled out and most of our users returned.
Lesson learned was that people hate change but if it is change for the better they'll generally recover from it.
It reminds me of Microsoft's change from Hotmail to Hotmail Live, which took 10 times longer to load and glitched constantly and I now have like 400 unread emails because I stopped using it. I now have a domain name in my own name so I literally tell people my email is (first name)@(full name).com and it works so much simpler.
However, the ironic thing is my email is hosted on the same server as my brothers, yet I haven't seen or emailed him in like 6 months.
That fact that they need classic Facebook so much they're willing to become a 'developer' to exploit a profile work-around means they're more addicted to Facebook than the average user.
It's a win-win for FB.