One thing you need to keep in mind with all this is the fact that the Spaniards can open and close the gates - and there are actual gates, not just a barrier - into Gibraltar at will (and frequently do). These same gates were locked for 15 years - not very conducive to swelling your passenger numbers, whatever price you are charging!
From Wiki:
In the 1950s, Franco renewed Spain's claim to sovereignty over Gibraltar and restricted movement between Gibraltar and Spain. Gibraltarians voted overwhelmingly to remain under British sovereignty in the Gibraltar sovereignty referendum, 1967, which led to the passing of the Gibraltar Constitution Order in 1969. In response, Spain completely closed the border with Gibraltar and severed all communication links.[21] The border with Spain was partially reopened in 1982 and fully reopened in 1985 prior to Spain's accession to the European Community.
If Britain voted to leave the EU, I think it would leave Gibraltar in a very difficult situation.
With this uncertain background, if I worked for route planning for a major airline, I don't think I'd be suggesting opening any routes to Gib!