There has been some discussion on the list about the need for a logical query language -- and by implication, the need for a non-trivial query planner.
I don't have an opinion about what is the right decision for Apache Drill. It depends on the goals of the project, and I have not heard a consensus emerge on this list. (I was hoping to hear this at this afternoon's meeting.)
However, the way I see the world, if a data management system has a logical/physical separation, there are many more pros than cons.
I will prepare a few slides explaining my point of view. May I have 5 minutes to present them at this afternoon's meeting?