I'm not entirely convinced that Jet2 would go to CWL, however I don't think it should be completely dismissed. Who knows in this industry?
CWL is known at being profitable for Airlines during the summer. It's the winter months that are the issue. WW stated they were profitable during the summer, albeit over 6 years ago now.
WW operate daily, sometime double daily PMI, ALC and AGP. IBZ, MAH, MJV, FAO all served and currently still under served from CWL.
Further afield FR don't seem to making too much of their TFS, now twice weekly service.
ACE, FUE, LPA Cyprus and Greece would be good options.
I would say Jet2 may favour BRS over CWL. They had no issues in getting into BHX with all the competition there. BRS has a much bigger and wealthier catchment area. The only issue would be BRS is more or less operating at parking capacity. I can't see there being enough stands for based aircraft, given that there's now talk of a 14th based Easyjet aircraft.
CWL has taken a dive within the past 5-8 years but things are picking up since the government takeover. Maybe Jet2 could benefit in some of that support? I've no doubt Airlines have lost confidence in CWL, especially with uncertainty in the Welsh economy. On a plus note Vueling are continuing to grow slowly.
Other carriers have tried and failed to make Cardiff profitable. Jet2.com isn't a charity, there's got to be profit in it to make the investment there
CWL has had bad luck with the carriers it's had.
WW had bigger problems than just at CWL.
BE were more domestic, but have now returned.
The other failed carriers were mainly Long Haul. TOM favoured BRS with FCA merger,
Zoom went bust, Globespan went bust, XL Airways went bust - but all were doing fine at CWL. Zoom were slowly growing, globespan went busy before the flights started and XL Airways had operated 747's and then onto A330's to SFB.
Then CWL felt the effects of others consolidating. FCA and TOM, MYT and TCX, Goldtrail, Holidays4u going bust.
So although I don't think CWL will be a massive earner for any Airline I don't think the bucket and spade market is a doomed failure. It would provide a footfall to provide competition to FR and EZY in BRS, as well as TOM and TCX in both Airports. It could be an easy ticket into the Southwest