[jolmg]

The alphanumeric codepoints are well placed hexadecimally-speaking though. I don't imagine that was just an accident. For example, they could've put '0' at 050/0x28, but they put it at 060/0x30. That seems to me that they did have hexadecimal in consideration.

[kubanczyk]

It's a binary consideration if you think of it rather than hexadecimal.

If you have to prominently represent 10 things in binary, then it's neat to allocate slot of size 16 and pad the remaining 6 items. Which is to say it's neat to proceed from all zeroes:

    x x x x 0 0 0 0
    x x x x 0 0 0 1
    x x x x 0 0 1 0
    ....
    x x x x 1 1 1 1

It's more of a cause for hexadecimal notation than an effect of it.