This debate is missing the fundamental point that air services do not depend on the size of the city but on the market potential for the service in question. The two do not always coincide as neatly as you may think. In the case of Emirates, Glasgow works because the catchment area has a much higher proportion of residents whose ethnic origin is in the Indian subcontinent and Far East than Edinburgh. This is a key factor for Emirates to make the Dubai hub work [and it's also why you have PIA at Glasgow and not Edinburgh, but I don't see anyone arguing to try to get them to Edinburgh on here].