Turns out it's a lot more complicated than that. "Points", and in particular, the abbreviation "PT" for it, is used in Competition mode, and it is separate from Score. You can't easily use "S" either because of the constant usage of Super Sonic, both words starting with "S". Many icons were thought up, and most of them ended up not working in one way or another. It's not that we all went "LOL TOUHOUS" like a lot of people here seem to think. There simply isn't a good way to represent "score" in a 12x12 icon, and the 点 kanji ended up being the one used.
Now, I'm not in objection to changing it, personally, but any replacement has to do BETTER, which means it needs to mean the same thing in all contexts, regardless of culture. For instance, one of the designs we debated was the # character, meaning "number". Unfortunately, # doesn't actually mean that everywhere it's used. In most European countries, # is a hash and doesn't have the other meaning it does in the Americas. Many other commonly used icons and symbols have different meanings in different cultures. Believe it or not, a check mark means a wrong answer in Japan, for example.
This is part of the reason why using 点 works. It has a specific meaning and the player will either recognize it and what it means or won't. There isn't a circumstance where the player will recognize it but think it means something else. It also fits just fine in a 12x12 icon, which is another nasty restraint.
Now, I'm not in objection to changing it, personally, but any replacement has to do BETTER, which means it needs to mean the same thing in all contexts, regardless of culture. For instance, one of the designs we debated was the # character, meaning "number". Unfortunately, # doesn't actually mean that everywhere it's used. In most European countries, # is a hash and doesn't have the other meaning it does in the Americas. Many other commonly used icons and symbols have different meanings in different cultures. Believe it or not, a check mark means a wrong answer in Japan, for example.
This is part of the reason why using 点 works. It has a specific meaning and the player will either recognize it and what it means or won't. There isn't a circumstance where the player will recognize it but think it means something else. It also fits just fine in a 12x12 icon, which is another nasty restraint.