As a host on Xplay, the only reason he even scored games is that it's what people want. I seem to remember him saying that it was forced on him but I can't remember for sure. His point was that no one can concretely answer "what's the difference between a 92 and a 91?" So he decided that it's be a scale of 5. 5 is reserved for the best games and 1 is reserved for games that flat out sucked. More than anything, he felt that games needed to be explained and critically analyzed to be judged if they're actually "good" and a number doesn't do that. They're all based on individual preferences.

I would say you're probably right that as far as numbers go, you're probably right that it's the best we've got. But I'd encourage people to look at forums or spoiler-free reviews to see if it's good for them.