I do remember the Pick greybeards being dismissive of this new fangled SQL stuff: "we had relational databases before SQL don't you know"
How much use all these different ports saw, I don’t know. Obviously some of them were pretty big (you mention Prime, I’ll mention R83) - others less so. I wonder how many customers IBM RT PC PICK ever actually had. Probably significantly less than PICK ever had on AIX for RS/6000 (at one point several different PICK vendors offered Unix ports, and AIX was commonly on the list of supported Unix flavours)
I hate it.
According to Wikipedia:
Approximately 23,000 RTs were sold over its lifetime, with some 4,000 going into IBM's development and sales organizations. Pick OS sales accounted for about 4,000 units.