Why do developers make their default keybinds impractical?

Controller mappings in most games work good enough, but keyboard and mouse bindings, even for games with great controller mapping, often have poor key placement. Even though preferences differ, no one wants to be reaching across the keyboard, and I don't want to analyze and troubleshoot keybinds for each game I play.

Why aren't developers optimizing keyboard bindings the same way they do controller presets? What's your method for adjusting key binds?