The only reasons I can see for refusing such efforts are (1) Michael hated Terri's family and wanted them to suffer [a possible reason, but not a legitimate one], or (2) Michael was afraid that such efforts might succeed [another possible reason, but again not a legitimate one]. Care to offer any legitimate reasons?
The swallowing tests were done in 1991, 1992 and 1993, and from the GAL's report that was a time when there was no disagreement between the Schindler's and Michael Schiavo. So it would appear it was neither reason (unless someone can provide contrary evidence). You'd have to ask her doctors at the time, but since she failed three swallowing tests, I assume they thought that the risk of aspiration was held to be very high.
Is it impossible that someone good improve on their own over say the next decade or so with no treatment? 1993, yes, that was the year Michael got the rehab funds. Correct?
Perhaps I was unclear. When the option of using a G-tube to feed Terri was available, it would be reasonable to use it if there was any meaningful likelihood that oral feeding could cause aspiration. When the G-tube was removed, what reason was there for not attempting oral hydration and feeding? That Terri did not choke on her own saliva indicated that she was able to swallow a significant quantity of liquid. The risks of oral feeding may not have been worth taking when there was a viable alternative, but when no alternative existed, what meaningful risks were there (besides the "risk" of success)?
Suppose the risk were 75%. Would it be worth trying to orally feed a patient if the alternative were to feed the patient via g-tube? Certainly not. But if g-tube feeding were no longer possible and the alternative was guaranteed death by dehydration? In that case, the 75% risk would instead become a 25% chance of survival. Hardly great odds, but not worth dismissing either.