Anothertyke is probably right to question whether the EC considered LCCs when setting the rules. But that isn't the point, which is that the rules are now clear (at least in relation to technical delays) and airlines have no option but to comply. The compensation levels are set by the directive, and cannot be varied by the CAA or any other national body. By all means lobby for a change, but in the meantime comply with the rules as they stand.
As has been pointed out by others, Jet2's notoriety in relation to EU261 claims will only encourage people to claim. It has only itself to blame for being seen as tricksy. And it will take a long time for its reputation to recover.
The CAA's full report will be published tomorrow, showing how a wider group of airlines (not just the bad boys) are complying with EU261.