As I'm currently in the business of creating a fuel calculation system which includes both legal reserve requirements and the flexibility to allow users to edit the assumptions - for example, to limit the FL assumed for diversion to the alternate rather than using 'best FL' figures, I am naturally quite interested in this topic.
However, when this topic was first discussed following the 'Spanish experience', it was clear to me that many 'professional pilots' don't actually understand the definition of 'final reserve' or even 'alternate' fuel. Typically, some thought that 'alternate fuel' included a 5% contigency allowance while others thought that, even when an alternate was required, 30 min holding fuel had to be included at destination, rather than at the alternate.
Having studied the IAA report, the reserve fuel carried by the affected aircraft seems to me to be entirely in line with EASA requirements. But when there is a strong possibility of being air-trafficked in a less than competent manner, a wise captain should bear that in mind when deciding alternate fuel, in my view.
If a diversion is managed normally, the aircraft will land at the alternate with final reserve (30 min) plus any unused contingency. The problem comes when the diversion cannot be managed normally, due to weather/poor ATC/other aircraft also diverting - and that's when the captain's airmanship decision is validated. Should an airline's management policy discourage, or even penalise, a captain using his/her experience and judgment to decide the reserve fuel to be carried, then that airline should well be open to question.
In my personal opinion, I thought that the Ch4 programme was naive and sensationalist. Frankly, I didn't see the point of it.
I choose not to fly Ryanair not because of any perceived safety issues, but for various other reasons.