[rooboy]

Spoiler for Yes, probably now OT:

*sigh* but it wouldn't be a problem if everyone was a "discriminating viewer" like I am.

More seriously, I've always assumed that viewer bias was the reason why there's not more qualitative numbers associated with ratings. For example, some people on this site tend to rate things no lower than a seven if they finished watching it simply because "anything lower than a seven is not worth my time". They then spend years deconstructing exactly how bad the show is.

Generally the way I've always heard it described, advertisors want better information (that's what drove Nielsen to include the TiVO information), networks want less. The network already understands the rules of the ratings and (generally) how to keep ratings high for shows, so they benefit under the current system. The advertisors don't care about the ratings game except how it impacts their ability to touch their intended audience, so they care about better information.