Because you don't know what changes were included, by who and how stable they are? That doesn't say the build IS bad, but it CAN be.And why is that a bad thing?
I don't really get why I have to justify myself this much for just a simple request. A clean late build of cm-11. Personal preferences, paranoia, whatever reason, does that really matter? If someone has it: great! If no one has it: bad luck. That's it, no harm done, time to move on.
You might not have any objections to a random build, fine, that's up to you.
The fact that I mentioned my findings in this thread is to inform others who might go download the build. They might have similar objections. At least now they can decide for themselves knowing what kind of build it is.