I'm not against the idea, as I'm sure it would allow a larger number of people to contribute. The only problem is so few games so far haven't required some sort of weird totally different piece of code here or there to work correctly. Marble Madness uses 2 bytes to store 3 characters for the name, 1942 stores the scores in whatever order it feels like storing them and using a byte to determine where it shows up on the list of scores, some games like Donkey Kong Jr. aren't symmetrical when it comes to scores, and the list goes on.
It would be an ideal solution if we could come up with a format that could deal with these quirks, some sort of byte mapping solution maybe. For example take Marble Madness. It's a 50 byte file with the current hiscore.dat, and stores 10 scores. It could be listed in a .hid file as:
"0-2", "Score1", "Reverse,HexToInt"
"3-4", "Name1", "MarbleName"
"5-7", "Score2", "Reverse,HexToInt"
....
"2E-30", "Score10", "Reverse,HexToInt"
"31-32", "Name10", "MarbleName"
While this seems like overkill matching up every single byte, it's probably necessary. If this seems like something everyone thinks is a good idea, I'll see what I can do to start implementing this. However, I still think certain games would have to be completely custom (1942).