No, its because incremental performance and error recovery are more important than raw performance and expressiveness. If you think Dr. Odersky doesn't know enough math...not to mention most production compilers out there written by the best professionals in the field. Reality is a harsh mistress.
My parsers, by the way, do things only your parsers could dream of:
Yep. Well, see my managed time paper; basically we use no fancy algorithmic tricks and it all works out fine. There are 2 ways to do incremental parsing: the hard way based on some fancy delta algorithm, and an easy way based on simple memoization and conservative recomputation.
Academics especially often over think these problems when the simple solution often works fine, and performance wise you'd have to mess up pretty bad before parsing becomes a noticeable bottleneck.
My parsers, by the way, do things only your parsers could dream of:
http://research.microsoft.com/en-us/people/smcdirm/liveprogr...