That's what it already looks like.
Ryanair came in 1999 and expanded until 2008 after which they have continually retrenched with the airport losing Tenerife, Birmingham, Bristol and East Midlands with Stansted cut from twice daily to once daily.
Apparently the impetus to commencing operations at Aldergrove is the availability of a Gatwick slot but they are also apparently promising 1 million passengers on new routes to Germany etc. If air passenger duty isn't an issue then why could this not have been done at LDY?
If Ryanair have no commitment to the airport then throw them out. Now I understand that the problems at LDY are not just the airport's fault and that there will continue to be difficulties so long as the local economy continues to suffer blatant discrimination from Stormont in provision of university places, lack of decentralisation and Invest NI only promoting Belfast etc but in the meantime if Ryanair aren't part of the solution then they're part of the problem.
Throw them out and rebuild from scratch. The continued presence of Ryanair is deterring additional operators.