Well no. Death's Design is critical to RPR's rotation. Enshroud has a 15 second recast and Arcane Circle only lasts for 20 seconds. To get a second Enshroud off under Arcane Circle, it has to be activated 5 seconds earlier (i.e. about 2 GCDs). Those 'dummy GCDs' have to come from either Shadow of Death or Harvest Moon. To get two dummy GCDs out of Shadow of Death without overcapping on Death's Design, you need to have about 9 seconds left on Death's Design when you enter your two minute burst phase. This means that you have to deliberately let the timer tick down in preparation for your burst. If you took that setup away, the debuff is just fluff.

In AoE, Death's Design has the added feature that it gives you gauge on mob death, which is a neat effect in itself.

I think that it's relatively easy for the dev team to come out and say 'behold, a 30 second GCD-based DoT' on every job. Part of the playerbase would struggle with it, but I think a sizeable portion of raiding players would manage it as automatically as breathing. The interesting part comes out of the interaction with other actions. Can I refresh all my DoTs with a single action (Iron Jaws)? Can I spread them to another target (Bane)? Can I freeze the timers on them? Can I consume them for burst? I think if you can't answer the question around 'why is this mechanic here on this job?' then you're better off without it.