I get your point but don't glasgow uni have about 6 teams? They have a larger pool from which to draw players than anyone (other than Strathclyde and Stirling unis), comparing a local community club like Thorn with them is an unfair one. However Thorn would definitely be a loss if they left the caley as they've been excellent since joining.
Perhaps Thorn will try and get a local youth side, maybe Johnstone Burgh 21s to step up and be Thorn's new amateur team?