Roger has always been dismissive of the band’s 1960s efforts so perhaps he was using that as an excuse to dodge having to give much detail.
Nick Mason has been touring playing 60s Floyd material, and I believe Roger made an appearance at one of the gigs.
One of the coolest things, IIRC this may have been Bowie’s last live performance.
Arnold Layne - David Gilmour w/ David Bowie
https://www.youtube.com/watch?v=LmvtsBPz6Io
Here’s an interview where Roger gets into details about his drug use. 4-5 years of lots of hash use and he said he took acid twice.
Not sure that by itself would explain his warped political views. Some people did as much as that and ended up as conservatives. :-)
https://www.dailymotion.com/video/x4z2b4r