WASD makes good sense to me too... just not so much in SH. Other than being shooter's habit, there's really no reason for these controls in SH5. Mods for SH3 and 4 have free cameras too, and those were always using arrow keys.
As I said, this is mostly for old SH players who feel weird diving with anything other than a D, C or P
These are easy to change BTW, just takes a little digging and copy-pasting in the config (took me a couple of hours to find, edit and test commands to my liking).