What all of you ranting above seem to forget is that airlines will maintain services from an airport if it is financially viable to do so. Clearly airlines have decided that there is more money to be made elsewhere. Changing the management and stamping your feet will not change this simple truth.
In the summer leisure travel makes money for some operators less so in the winter. Domestic flying from most smaller airports is at best marginally profitable and at Cardiff less so.
You can all have wish lists as long as your arms and look for scapegoats, but that will not change the economic reality.