"Also to be fair, if you have some mileage on your odometer, your pattern-recognition machinery will quickly assign high probabilities to various outcomes."
His combination of personality and experience is leading him to draw conclusions about where Racket2 is headed that is causing him to press pause on using (and contributing to) Racket. I had a similar reaction (described in this post: https://www.travishinkelman.com/post/exploring-scheme-implem...).
It seems that you are not assigning as high of probability to the outcomes that Greg is concerned about. Or you are not as concerned about those outcomes.
[1] https://wiki.call-cc.org/eggref/5/pstk
[2] https://akkuscm.org/packages/(rebottled%20pstk)/