Is there a reason why I cannot customize KB-M PC controls in this game or is it that badly optimized on PC!?  Because seriously in 2019 there should be no reason why you can't customize controls on a PC game.

Hi, quadphonics

You should be able to edit Keyboard and Mouse controls through the Settings menu under Controls by clicking Edit Keybindings.

However, if your issue is that you tried that and it's not working, please contact Private Division support and submit a ticket to help expedite your issue's resolution.
You can submit that ticket by following this link: https://privatedivisionsupport.zendesk.com/hc/en-us
 

Thank you, and sorry for the inconvenience this is causing.

I literally could not find any menu for doing key remapping. There does not appear to be one under Settings. Settings seems to be exclusively for graphics options.

Settings->Controls->Key Bindings