Re: Same impression here
"X-Windows and Motif, however, were a whole together different kettle of fish. Did the job, but buggy as hell, and highly idiosyncratic."
To an extent, yes. But with a bit of practice and attention to (poorly documented) details, it wasn't that difficult. I never had an opportunity to do much X/Motif development. But I have done some Perl/Tk interfaces. Not really all that difficult.
"If it weren't for the flakiness of that particular platform, I doubt that O'Reilly publishing would be the power house it is today."
If I recall my last peek at my O'Reilly manuals, they were little more than reprints of the X/Motif man pages. Back in my days at Boeing, we got a set of these shipped with every HP workstation. Most of them ended up in the dumpster, never unwrapped. So have got a complete set at home (somewhere).