Now that the tournament is co-sanctioned with the PGA tour a lot of the recent courses are out of the question due to the size of the operation. Every year more stands and refershment zones are being put in - only 'quiet' section is on the Muirfeld boudary (and obvs the 13th)
Inverness and Aberdeen wont get the size of crowds that are now expected/required - Gullane would require a composite course and having most of the courses out of play for build out etc.
Thinking back to when it was at Dundonald in 2017 never mind back to loch lomond, it was a MUCH smaller setup to what we see now.....
File it under a course thats OK but chosen for logistics over quality - they will work on the experience for players and patrons.