The problem with this route is it's a low yield and very high cost for the regionals.
The pax figures aren't great, whenever I travelled it was mostly crew on SB tickets positioning to/from work!
LGW is big money to turn an aircraft round, I was quoted a return ticket price of £300!!!! Got the good old GNER from Kings X!!!! - in short, don't think the economics add up but it was very useful when it was operating.