Because people as usual are "assuming" it was "minor" changes rather than realising that a lot of the stuff was fixing memory leaks and other behind-the-scenes issues, that you will only notice are fixed when you have been using your device for a week and realise it hasn't slowed down like it used to.

Its known that they spent a lot of time fixing bugs in the graphics driver and MicroB, many many memory leaks and other things which you wont necessarily notice the difference on day one but drastically improves the stability of the device over a longer period.

Also I know it would be painful, but I think Nokia made a big mistake allowing this update OTA. They moved a lot of stuff around from the NAND to the eMMC and its clear the best way to update is to backup, copy everything off in Mass Storage mode then do a completely restore to factory PR1.2 by flashing FIASCO and eMMC. Knowing that a lot of stuff is being moved around I did it that way and find scrolling silky smooth and while I have had a few stutters where I click something and it doesn't respond for a few seconds, it seemed to calm down after a couple of hours and is now faster than ever.

The problem here is people expecting an OTA update to work as well as a complete reflash and Nokia are partly to blame by allowing it. OTA works better if you do lot of small updates rather than occasional big ones like this one. If you want to reduce your chances of problems, backup, copy everything off in Mass Storage mode then reflash EVERYTHING!

I'm not saying you wont have problems, but I think quite a few in here are caused by people updating OTA or flashing the FIASCO image but not the new eMMC. Most of all, its people not knowing what they were getting themselves into buying a Linux phone. As a long time Linux user I knew all too well that there would be missing functionality and that installing applications could break the ability to update properly.