But that doesn't explain why EZY are still growing in other markets.
Well you can't argue, it's fact that SEN hasn't contributed any growth to EZY since they have taken more capacity out of STN than they have added to SEN.
With Stelios being anti growth, any expansion has to go where they got most bang for their buck, that's not STN at the moment. Remember EZY also closed EMA and have hardly made much of a dent in Scotland, unlike Ryanair which has gone Hell for leather for growth and cutting costs but as the two businesses mature, arguably EZY is in a better place.
The thing that is "such a shocking way to do business" is EZY continued inability to be able to expand at one location, whether it be LGW, LTN or SEN without it be at the expense of another.
It's only "shocking" when you as an outsider only have a partial picture and certainly have not seen the revenue numbers from EZY. All the London airports compete with one another to a certain extent, LTN/STN especially so, it would indeed be more "shocking" if they offered the same routes from each airport.