I can think of several possible reasons why SEN is not faring well in attracting new airlines and routes. The SEN price structure may - or may not be - one of the issues. That is why I am interested to hear further details of the CAPA report in particular how they reached their conclusions so we can assess their relevance to individual airline situations.
The CAPA report surely can only rely on the published brochure figures and cannot have access to confidential commercial information that reflects the deals actually struck. Skywork and Adria are two airlines that presumably would not agree with the CAPA contention that SEN is the second most expensive London airport.
For sure there is a sizeable contingent of spotters and enthusiasts who contribute to this thread, and their enthusiasm may often be unrealistic. But that is harmless. There are also those who seem to only come to this forum when they want to post negativity. If that negativity is not based on sound evidence then it may become destructive. Then one starts to question motives.