I haven't noticed any "poor me" Manchester comments - more surprise on just how deep the cuts are for next winter compared to previous years. This can only be due to a larger than usual downturn in expected travel demand for whatever reasons. If the demand and profit was there the airlines would provide the supply.
MAN has always struggled with much lower winter demand to the USA compared to summer. Airlines have traditionally reduced frequencies, or in some cases taken a complete break from January to March. Take JFK for example where up to 4 daily wide body services operate through the summer months, usually reducing to 1 or at most 2 daily in the winter. Next winter looks particularly thin, but having said that MAN has fared better than some airports who have lost their transatlantic links altogether.
As someone else said it's cyclical. We've had the boom, now we appear to be on a downturn. When demand returns so will the flights.