Erm, are you sure you haven't looked at how many domestic flights there are between London airports and Central Scotland ones? Are you seriously saying flying is "not normal" to those who use these routes regularly? There's a wide choice of flights every day... Then add the ones from Aberdeen and Inverness and the small selection from Northern England...The United States of America covers around forty times the area of the United Kingdom and the distances for domestic journeys are many times greater than for domestic journeys within Great Britain. For this reason flying is a normal way making domestic journeys within the United States of America.
There are a meaningful number of other pairs between airports in Great Britain which all run several weekly services. This is a far lower intensity, of course, especially since Flybe collapsed (twice), but the way you describe it is as if this is rare. It's not...
