No. You can say you think a game is "bad" or "good" without needing to apply some sort of number to it.
The number is nothing other than a representation of "bad" and "good". Horrible games go in tier 1, bad games go into tier 2, mediocre games go into tier 3, good games go into tier 4, and great games go into tier 5. 1-5. So when you say a game is 4, you are saying that it's level of quality, it's peers, are the level of "good" - not mediocre or less and not great.
EDIT: This is not necessarily a number. You could use colors, hand gestures, symbols (although numbers are also symbols), etc. All means the same thing though.
EDIT: The judgment I'm describing here is almost always being made in an enthusiast review, all they are doing is making it less clear. (Reasons being obscurity means you have to read more or makes it harder for metacritic to sum them up.)
EDIT: Other points:
"Scores are inconsistent throughout a website" - that's because websites employ more than one person. Value judgments are subjective to the person and scores are nothing other than clean and tidy value judgments. That's all it comes down to. You can argue that they do not use the scores equally, but even that's subjective. "How good does a game need to be in order to count as good?"
"People get mad at the score" - People get mad at other people not liking the game they like (or the opposite), especially if they are in a position of relative power. As long as their approval or disdain is expressed clearly, the reaction will remain the same. Scores just make that more visible, because it is a more visible expression of one's final assessment. Even in those cases, people, as you can see on GAF, still look through review for quotes to see why they would give such a score. You can say that people will be quicker to dismiss someone who gives a good game a bad score, but there's really nothing with that insofar there's nothing wrong with dismissing someone who calls a good game a bad game. It just makes thing more clear and direct.