There has been a lot of talk of the reduction in the GRO service to 4 x weekly for IATA winter season. This is only for the winter and the service returns to daily for the IATA summer season next year.
The reason for the reduction is simply the route is much stronger in summer than winter, seasonal variation. Nothing to worry about, its just the way the business goes.
With regards to putting all the eggs in one basket, I will point out a few facts. Firstly, Ryanair operate 3 routes, Jet2 9. Yes, well done. However, in terms of volume, even next summer when Jet2 are operating up to 7 flights per day, Ryanair will still account for around 45% of the airports business, with Jet2 around 45% and the balance being Monarch and the Irish Sea Traffic.
So, hardly eggs in one basket, but a healthy mix between 2 well established and sustainable carriers. I would also point out that for many years LPL had around 80% EZY so in all I would say BLK is doing rather well!