Actually there are a lot of system implemented hotkeys that are unchangeable.
You may propose this in special thread for all interface suggestions:
https://us.forums.blizzard.com/en/sc2/t/sc2-interface-suggestions/15769/55
It’s better since at least people are trying to maintain enough popularity so it won’t be flooded by whining-on-balance-one-shot-threads like it eventually will happen in your one.