Luckly i play windwalker where weapon ilvl barly matterI daresay it was a problem. Getting good or shitty RNG on your weapon drop could dramatically affect your DPS. I remember playing Fury in HFC and being kinda shit overall, until I won a Mythic weapon off Fel Lord and bonused another, then I shot way up in DPS. On the other hand, our two Rogues had to wait literally 5 months into Mythic before both had Mythic daggers. Let's not talk about these poor, lonely and useless hunter weapons.
Relics provide a more staggered power increase, so that RNG is mitigated; it usually won't be so bad that all of your relics are awful or balls-out amazing. Weapons are an all or nothing deal.
And Titanforging will make the issue even worse. Imagine lucking out a max level TF weapon early in the tier while others have to stick with Normal or Heroic weapons?