But not everyone does know how to flash, and therein lies the problem.
I've had my N900 for 16 months and have never reflashed (except for the upgrade to PR1.2 which told me I needed to do it from the PC not OTA). I;ve never reflashed because of a problem anyway.
I started overclocking 4 months ago, feels like a new phone now. Barring a few minor annoyances with ulv profile, no major hiccups or lockups. I have a fair few devel apps installed, but not loads. I recently upgraded to Pali's power-v47 and it is great. No issues here again, and I regularly keep the phone over 1Ghz.
Problem with noobs is, they see all the apps in extras and devel and they install them, all of them, because they are there and because they can. No thought goes into what is required, why they are installing it, and what it may possibly do to their system. No thoughts of anything going wrong, just install it and wail afterwards demanding help. That's life and it sucks.
If there were no warnings about devel, then fair enough, but they are put up, often, to try to stem the flood of ensuing "help me" messages that would drown this forum completely.
The way to learn is to get in trouble and get out of it. The first thing I learned was how to flash. I don't think many users of any level pay attention to the devel warnings because they are mainly wrong.
I used to but found that it caused instability for a few programs whether it was OCed or not. Modrana was especially obvious but I had lock ups/reboots in other programs more often as well.