Agreed, there are good financial and environmental benefits to be had from moving kick offs . 3pm kick offs are traditional only because Saturday was for many supporters a ½ day at work and 3pm let them finish, have a pint and get to the games. For the vast majority of clubs it would be worthwhile although I saw the ICT chairman dismissing the idea because away fans wouldn't travel to Inverness for an earlier kick off (although he didn’t say if he had approached any clubs to see if they were in favour or not)
I emailed Thistle a couple of months ago asking if moving kick off times was under consideration or being discussed with other teams in the league. Still waiting for a reply.