>>96402212
Space Marines are just the sci-fi version of chaos warriors but for good guys. So really the blame is one chaos warriors and how cool they are in concept and design that GW had to make a version of them for the good guys. Instead of praying to chaos they pray to the Emperor, weird armour unqiue to them they never remove, utterly devouted to war, better than a single person in combart, bigger, stranger and scarier etc.
So really its chaos fault