Airports play a part in growing the economy. If CWL wasn't there, yes many people would simply transfer to using BRS, but with that so may some industries.
The key element is that CWL isn't just there to take people on their holidays, it's there to provide links to businesses across the UK, Europe and the World, which will help grow the Welsh economy. This isn't something that's going to change overnight, but is already happening with the links provided by BE and now QR.
Governments bail out companies all the time, especially in Wales and the Airport is no different to that and key to helping the Welsh economy.
CWL needs to start somewhere, as it was left to deteriorate over the years, both structurally and commercially. People on here seem to expect things to happen overnight and it to become an instant success. Wales and the WG is pitching itself to the world, which will help the Airport grow as inbound tourism and business will grow. It's small steps but BE is continuing to grow and is rumoured to be happy with the success of CWL. Hopefully QR will be the same.
Given the current state of the Airport, the investment is needed. The work that's gone into growing the business once more is slowly paying off, but is not going to create instant profits to do the work that's really required now. It's an investment by the Welsh government, not only in the Airport, but in the economy.