That makes a good story for no re-vote thus far but the basal reason is the interests of the big powers, San Jose-SVLG and the Ranch-Palmdale developers would be undermined.

Those two cabals, along with Fresno, managed to capture control of CAHSR route selection. Naturally those two would be loathe to see that control wrested away. Curiously Fresno could become relatively agnostic on the route choice as they would not be hurt by a move to Altamont and Tejon, possibly even benefiting.

The 800 lb. gorilla of NorCal transport, namely BART-MTC-SPUR, have not been heard from AFAIK. They would generally oppose the DTX funding as it stands in the way of bechtel gauge colonizing Geary, their holy grail. I could see the possibility of a gentlemens agreement that serious money from CAHSR would come to them in the event(highly unlikely)their huge upcoming tax measure should fail at the polls.