The context you're missing is that Ryanair have routinely declared fuel emergencies in the past, and it seems an operational tactic - they want to carry less fuel to burn less fuel, and then have to regularly mayday to jump the stack on inbound, saving cash. That's not covered in the article, but you can sure as hell expect the CAA are going to take another look at them and their operations planning.
On this one, they did 3 attempted landings at Prestwick. [Edit: I now see that the third attempt was at EDI] What happened between the first and the second landing that made them think on their second go-around that a third attempt was more likely to succeed than the previous two? Was the wind dying down, or was the captain just feeling a bit braver or stupider? [Edit: I'm still curious as to what information they gathered that landing conditions were significantly different at EDI to make that diversion, given its relatively close and so likely to have similar weather].
Why was their final reserve Manchester when there were literally dozens of closer suitable airports, at least some of which are likely to have had better wind conditions by virtue of lower gusts, or more aligned to runway direction so not dealing with a strong crosswind?
There are many reasons I won't fly Ryanair, but not least because they have been shown over and over again to make reckless planning and operational decisions, and they are fortunate to have not had hull losses as a result. Time is ticking down, variance will catch them one day, and a sad & tragic catastrophe is only a matter of time. People will go to prison as a result, because this pattern of behaviour shows that this isn't "bad luck", it's calculated risk taking with passenger and crew lives to save money.