For a long time humans have believed that knowing the true name of something is powerful. So it is. However, as any programmer who has tried to name functions/procedures/subroutines will tell you, it's not easy to get it right.
In computing the power of a name is in its ability to be mnemonic, so that you can remember what it was when you go looking for it, and meaningful, so that someone else has a clue what's in it. Historically there have been limits on its length and the characters it can contain. We often continue to adhere to these limitations whilst trying to cram various elements into this one label for the file.