I don't like it either but it makes sense from both a design and resources perspective. Your average RPG player would prefer being someone alive and sorta heroic. Just about every edition of Warhammer Fantasy Roleplay I did had only Empire, with maybe two-three classes for Dwarves, Elves, and halflings. This is just following that trend. The game would get massively delayed if they had to write out and balance shit across all four grand alliances. Comparing all of Order to limiting you to just a wizard is a false comparison, since Order is even more broad than even the old world 'good guy' races.