This happened because of nu-40k
>old 40k
>every army is unashamedly the bad guy. All are over the top, bloodthirsty warriors that desire nothing more than the complete slaughter of each other
>nu 40k
>Le noble and reddit imperium fights against le evil hordes of bad guys! It's like Age of Sigmar and Warhammer Fagtasy, dont you like it!
The idea of a Space Marine screaming incoherently as he charges into battle is the complete opposite of nu-40k. If this was a 10e era animation the marine would be silent and frowning before killing everything in a few seconds.