I would find it hard to question with CMU papers. They are a pretty thorough when it comes to computer and the tradition goes wayback. If I disagreed with something in this paper it would be a clue to myself that I need to understand the problem domain better.

I also think as a school the philosophy maybe to thoroughly solve the problem with out regard to speed because eventually computers will be faster.

I think the paper is just pointing out that anything great is going to migrate to the RM or SQL model. So that if you start there any feature missing will show eventually show up. They also point out how many resources go to deploying immature ideas.