 Why is Wyandotte didactic?
Rootless and footloose, a man in space can't help but dream of coming home. He was uncomfortable; Wyandotte seemed to know all about him. It helps suppress certain physiological reactions to an entirely new set of conditions. "The twelfth day is the worst," a grizzled spaceman told Craig. Either that or they had begun to produce ultra-sonic waves. They were now ready to become inhabitants of planets again, instead of free-falling ships. On the eighteenth day, automatic machinery freed them from their imprisoning cots. Then they again began taking paraoxylnebutal in preparation for the free-fall flight to Terra. "Not to Chociante, if that's what you mean.
 He thinks Craig will be a fish out of water in Terran society.
 He is likely being monitored by the Terrans and cannot speak freely.  He thinks Craig is an uneducated hick.  He knows that gravity conditioning is horrible. He is trying to change Craig's mind about going to Terra.  He thinks Craig will be a fish out of water in Terran society.