This isn't that surprising, given that Space Marines do it because they are the pinnacle of human perfection, helped my a large amount of gene modification so they are expert fighters. Ork Warbosses do it because dey like da dakka, but with an Ork's ballistic skill they never HIT with anything. Forbidding basic weapons makes sense, as does restricting heavy weapons in a swirling Melee combat.
On the other hand, space marines are dedicated fighters, I doubt they'd keep using (not many anyway) a bad combat style. As it currently stands in DW ruleset, it's way more effective to dual wield chainswords and drop one (free action) and Quick Draw a plasma pistol (also free action) when needed.