In the face of it I think there is perhaps an argument that's its maybe a little questionable, but your travel plans are up to you and your company and as such, none of our business.
You do raise an issue that, anecdotally at least, appears to be growing - that is more and more people from the GLA catchment flying from EDI "because it's cheaper". This surely suggests that, at least on some routes, yields from EDI are lower. It seems to me to then be a contradiction when airlines claim they make more at EDI and add routes and capacity at EDI rather than GLA. Can anyone explain this to me?
I can see possible economies of scale (and resultant cheaper fares) for airlines with a larger base at EDI than GLA (i.e. EZY), but in the case of an airline operating away based aircraft - i.e. BA LHR or LGW, I'm not sure I see how they can offer lower fares whist at the same time making more money. The obvious answer is that EDI are offering much cheaper charges than GLA, but this is vehemently denied by GLA people every time I've mentioned it.
The GLA LHR flights are always rammed with perhaps the e caption of the last rotation back to LHR and yes there are fewer flights and no competition. FlyBe have brought a degree of competition at EDI to LHR and LCY and I’ve been surprised at how full my FLyBe flights have been albeit more tourist connections than actual suits. Although with the business dress codes these days going beyond suit and tie it can be difficult to tell!