So an arrival at SEN would "leave the passenger with an expensive onward rail journey into London." would it?
I suggest you check the facts for the cost of rail fares from London's airports into Central London. The SEN to Liverpool Street fare will be very similar at around £13, and rather cheaper than from STN to Liverpool Street.
Stobart Group net debt at 28.2.09 was £120.7million, representing a gearing of 29.8% which is generally considered as low risk and their share price continues to outperform their competitors in their market sector.
I'm afraid your comments seem to be based more upon bias than fact.