Jerry,
For years the only international business type routing CWL has had has been KLM, KLM have had the monopoly, I've used them myself because there was no other choice from CWL ... Well except that outbound I was ticketed with Air France travelling in a blue F70 to AMS.
I see many of you singing and dancing that Qatar have announced a CWL route from next year but has it occurred to any of you that Qatar are to take away the KLM monopoly to M. East and Asia and this might just impact upon KLM's loads and cause them to reduce their frequency of services or pull out of CWL altogether?
Similarly if a competitor, or competitors, spring up in competition to Vueling don't you think that may similarly pee Vueling off and cause them to reduce services or pull out of CWL altogether?
Why does CWL need an expansion of services, has there been a baby boom in S. Wales in recent years? I'm pretty sure that if the loads of Vueling and others were so great they would be increasing their services by themselves and not need prompting by airport enthusiasts.
Don't go shopping for jam if the bread and butter is likely to go walkabout!