It's a personal choice, but how come Ryanair has 4 aircrafts doing the same thing when others don't seem to....!
I guess it might be a personal choice or whatsoever but if everybody has the same proportion of aircraft diverting in a mayday the system collapses. All the "our flightplan include SID/STAR stuff"...first it's the law which respecting seems like an absolute minimum, second it's for everybody the same.
It might be safe to fly minimum but sometimes it's just ridiculously stupid...TAFs and METARs are one thing, SID/STAR etc are the theory so what happens in those situations?ATC has to take you, first through CBs and use different routings as there is probably a lot more of a workload on them due everybody encountering issues (offtrack aircrafts, more aircraft piling up in the sector, reduced capacity and use of unusual holds). It's a really busy airport, do you really expect to get your standard SID/STAR trackmiles at optimum speed, anti-ice consumption etc...? You don't know what's gonna be the WX enroute to your alternate, central spain is a huge overheated high altitude plateau, conditions for TS creation if they prevail in MAD, they probably also prevail in its mid-range vincinity due similar landscape, terrain, sun exposure etc...MAD is south west corner of Europe, depending of the inbound traffic flow, it might be more crowded in the North sectors for last european medium haul coming in. If you hold north west of the airfield or south east it's not really the same story to go to VLC. Although there are the minimum legal requirements, if you have to go through all the traffic in diagonal, you're a lot more likely to suffer extra track miles to avoid traffic etc. Who's at low altitude between south east holds at MAD and VLC: nobody. Who's at low altitude between north west holds at MAD and VLC, all the traffic.
Then thinking you can still use the mayday joker card is just wrong and to me a lot of disrespect to others...you just put everybody in a more difficult situation with guys waiting for their turn in the hold being delayed due to your priority etc, increased EATs at last minute etc...it would be a disgrace.
Sea fog is a difficult thing to predict, it can happen really quickly with very specific conditions needing to match in very specific circumstances...TS in an evening summer in central spain doesn't seem to me that unusual.
But for all this, you need to gather experience, listen to experienced captains, and not just take the answer databases of the ATPL but understand the books etc...
If we just stick to the minimum fuel and listen 100% to the company orders then we are not much more than bus drivers...it's not a default of their pilots I guess. It just questions the real freedom you have regarding your fuel uplifts and consequences.
Finally, some airlines invest in controlling their operation. According to what I've read on the case, it seems two of those planes were really close to each other. The operations department could find a mean to communicate with their aircraft giving a heads up on what's going on with company aircraft. It's a mess just spreading the information might be a valuable input!