I agree. I think most programs handle this poorly. Folks argue about “standards” as though there was some meeting where every company got together and decided what the best shortcuts for commands should be. The reality of the situation is that it is simply easier for developers to copy the shortcuts of other programs when they add similar features. The fact that there are so many differences between their keymaps shows this.
If they really cared about making things easier for users who use their product along side other tools, then they really would have gotten together and created an actual standard they could all strictly adhere to.
Now as far as selection goes, I think blender was on the right track when they treated it as a toggle. Other software should really copy blender in this regard, not the other way around. I can only hope that the new default keymap treats A as a toggle again before it hits stable.