To implement a prototype of the future, this works well, but to sell something to consumers you have to implement something "cheap", which Xerox PARC didn't manage to do..
The timeline checks out though. The Macintosh came 12 years after the Alto was conceived, or 16 years after Engelbart's NLS.
And yet their innovations paved the way towards HCI paradigms we take for granted today. So although they weren't practical when they were invented, I think there's still value to these sorts of labs to continue paving the way for the practical creators of of 2034.