> the paper ignores the reason why people kicked and screamed for the functionality to begin with

No it doesn't. The explicitly talk about this in section 7: "The acceptance of Typed Racket in the commercial and open-source Racket community suggests that (some) programmers find a way around the performance bottlenecks of sound gradual typing."

> Reticulated Python is still an order of magnitude faster than Ruby

Are you suggesting that a slower variant of Python is ten times faster than Ruby? That doesn't match my experience. For what it's worth, Ruby outperforms Python in some benchmarks: http://benchmarksgame.alioth.debian.org/u64q/ruby.html