I don't always want to smash all my burns at once. If you can build macros to push the ones you want together then you have already simplified it no?
It does seem that if DBC did choose to simplify burns, they would still need some variety between short and long term burns. Even with simplification, you would still have discs, spells, and items to have variety and separate the best from the bad.
With all the adps type things. SPA's, ect, it would be nice to have a more coherent picture of this in game. Even out of game it's very much spreadsheet material.
Ehh, burns are pretty easy right now i think. Beasts have never been overly hard to burn, every class is essentially the same probably except for necro. (ive never played one though it seems more complicated or at least busy).
I don't think simpler burns are the answer. However, I would suggest that better feedback on stacking burns and abilities should be easier to obtain and utilize.