BA does this - GOOOD
Ryanair does this - BAAAD
5 flights, all with up to date forecasts and the ability to gain an actual throughout the flight, Short Haul, all with the ability to carry adequate diversion fuel to just about anywhere in Europe but not being given the 'authority' based upon fears of management pressure due to fuel league tables = BAD decision (from the company).
1 LH flight, no company restrictions on loaded fuel, just a minor niggle of max operating aircraft limits, 13+ hours at max endurance to an airfield the other side of the world with an acceptable TAF both for the destination and the diversion resulting in a declared fuel Mayday due to the weather forecast being inadequate/inaccurate? = GOOD decision (by the crew).
IMHO of course!