Mace Windu was being played and was going out that window regardless. You notice that Yoda was conveniently off-planet when Palpatine's true identity was revealed.
Honestly, if you know any amount of lore at all; Luke is far and away the strongest force user the galaxy has ever seen. You can hate it or love it, but Luke is a force demi-god. Abeloth had to be created to introduce real competition for him.
How can he, be the strongest force user, if one part of his parents pure force is and the otherone not force sensetive?