While Shannon is in an area which by virtue of its distance from Dublin depends on aviation for transport..... I'm puzzled as to why people are quite so shocked that routes have been cut.
There are plenty of people from central Europe (e.g. Poland) who are finding the bright lights of Ireland and the UK losing their allure, thus reducing the need for direct flights.
Further, in winter, in-bound tourism to west Ireland is not hugely appealing to many in Europe - it's a bit grim being outside when it's cold and grey.
The business market and the VFR market to the UK should hold up pretty well but I struggle to see the economic rationale for flights from an essentially rural area like SNN, to the USA and all over Europe in the depths of winter. Yes, I know Limerick is close by, but the whole of County Limerick has less than 200,000 people. When the economy takes a tumble, that discretionary trip to a Spanish beach in January seems like one of the easy things people can cut in their spending.