As you can see from my user ID I live in that wonderful scenery, and the Glasgow flight will be very useful to yachties I also deal with. I am also delighted that Glasgow's economy is recovering from the collapse of its traditional industries.
But, the population drift towards the East is continuing, and is predicted to continue. GLA is stuck with being on the wrong side of Glasgow.
I would suggest that the market for this route will not,in the main, be incoming PAX looking to admire our scenery - the scenery around Bergen is even grander. It will outgoing, many heading for a Norwegian Coastal Cruise (Hurtigruten), and I would have thought that Edinburgh would be a bigger market.
I think that it comes down to GLA being their main base.