Never fully understood what Jet2 sees the LGW route. As you say, they've got none of the connecting pax that BA had, so they need to appeal to London-bound passengers, or long-haul pax who dare to book a 'connecting' flight.
EZY are more frequent and consistently cheaper than LS (in my experience), and they have a much bigger profile.
FRA is a big gap. Not sure why LH only offer DUS - if they switch it to FRA, they could offer much better connections.
What about Sky Europe, Wizzair? Might we see something from them.
Glad that the Emirates route is doing well. I saw an advert for it during Channel 4 News the other day - first advertising I've ever seen for it outside NCL airport.