Windows8 is not in the market. Windows8 is still in alpha testing.... The earliest expected beta isn't until February. The Windows 8 Developer Preview is intended for, as the name suggests, developers. It's not intended for end-users in any way.
Thats your risk that you are apparently willing to take, it should not be used for production purposes, you might get lucky you might not, if not the answer will be a shrug of the shoulders and a DUH
Why are you insisting that it's so bad to use? It is a DEVELOPER version, it's purpose is to allow developers early access to Windows 8 to develop apps, already. If that is not a production purpose in it's own, then what?
Besides what's the risk of it anyway. You won't hurt your system, it might not run some things or not at all or everything just fine. That's all.
I was replying to farrengotu who is using it as his main OS. There was for instance no transition path from public beta win7 to full win7, they will in all likelyhood be no path from dev > beta > bublic beta > retail win8.
there may be undiscovered bugs, this is significantly more likely than in a retail version (and think of how many of those there are).
I was saying its your risk to use it as primary OS, and it is.