The simple truth is that any person could create a file that triggers a detection - and I'm not talking about a virus writer or a person who's already infected.
I've had it happen, in an intermediate file as part of a software build. Apparently something about the Win32:Evo-gen detection at the time was set a little loose because I'm not the only one. In fact, other than alerts on a few web sites that I wouldn't have gotten an infection from anyway (I disable ActiveX as a matter of course), false positives are the ONLY detections I've had literally in years. I do not rely on my AV solution, it's there as a safety net that hopefully never sees action.
Thing is, a LOT of people develop software and/or create content out there. Smart people. People who know what they're doing as well as any evangelist here, and who don't practice bad habits and get infections. I'll concede that it's probably no where near a majority of all users, but enough that there needs to be an expert option - or maybe an expert version - that provides expanded user control and includes better options for working around false positives.
This does not even touch on the possibility of the AV software having a problem that causes false positives.
Here's a good rule for any software developer to follow:
Make things easy to use, and as foolproof as possible, but don't dumb things down so much that they get in the way of smart users who know what they're doing.
If I had to summarize, the argument here seems to be between smart users who know what they're doing and aficionados who believe people would just get themselves in trouble if given control.
But, you see, the trouble is they DO have control. All or nothing control. This just needs to be refined.
-Noel