The entire purpose of competitive play is to win. The best way to win is to stack as many advantages on your side as possible. Just because its an easy advantage to gain, should it be passed over? Thats hardly a reasonable argument.
To borrow from other sources, a real problem is when there is a broken element. A broken element is defined as: a item/character/tactic that is so powerful as to centeralise the game around stopping that 1 thing. The example given was arceus from pokemon. Where arceus is involved, the entire focus of the party of 6 has to be "not being mualed by arceus." The best way to do that, is to use arceus, thus requiring every team to have an arceus or lose.
There are no such elements in dks (though some come close), everything has counters and nothing makes every match a race to exploit that one tactic/weapon/magic. Similarly, no one build is so powerful as to require