Not many clubs can boast about being in the 4th tier of their countries league and still get attendances of 45k! Fans in Scotland are very passionate about the game but the league is in trouble hence the need to revise the league structure.
Why would the irish and welsh leagues want to merge with Scottish leagues, you don't see less popular leagues like Belgian, Ukraine, Romanian, malta even dutch leagues (bar two clubs maybe) to a certain extend are not huge, why don't they merge?? Because it is not needed.
We are lucky to have a well supported league system so comparing our league to Scotland isn't fair.