Not sure if that is an excuse, but timing can be important here.
Broken Shore was a colossal disaster, one of the biggest events in Azeroth history. This could have been what finally made Odin decide to stop sitting on his ass and act - but that decision was AFTER Varian, Vol'Jin, Tirion and others died. So, at that point he was actively looking for an amazing non-Vrykul warrior to help him lead his armies, and it turned out he decided to select the player character.