the entire franchise exist solely because it has lore that allows it to exist,
the miniatures look the way they do because they are described by lore,
the games are based on characters and world building of the lore,
all art, armor, vehicles, cities, planets, gods, characters, from all species and cultures human or otherwise in 40k, is because of the lore,
as well as the plot its self and the scenes of events in the franchise are the way they are from lore.
with out lore you dont have sanguineous, horus, or any other primarcs and their stories or their sons, you dont have the chaos gods or the emperor of mankind, or eldar, necron or tyranids, or anything else.
with out lore there is no warhammer 40k,
the stories and world building from the lore is what allows the world of 40k and everything in it to exist,
and if you dont like 40k lore or reject its lore continuity,
than why pretend to be a 40k fan?