I think the OP sums this up. The more you run down a service and reduce it, the less people will use it. Ever decreasing circles, self fulfilling prophecy, etc.

This is what has happened at LGW. The only positive thing is the excellence of the LGW staff and, consequently, many aspects of the product. ^

On the other hand, if you improve a service, people will use it, as Ken Livingstone (remember him?) showed with London buses.

I am using LGW less becaue there is less going on there. No more flights to MAD, NCL, JFK, MUC etc etc. Not because I don't want to use it. Thankfully there are still MAN flights and they are useful to me.