In my experience, including training dozens of pilots doing their command courses, the problem is not necessarily commanders not having the willingness to upload sufficient fuel to cover known contingencies. Instead , it is the failure of many pilots who fly hundreds of sectors a year to properly make a plan to deal with a diversion once it becomes necessary.
These are high pressure situations where thinking time is at a premium as fuel is burned at a great rate. One needs to have a clear plan that complies with the commander's legal responsibility at dispatch. A plan that ensures that pressing TOGA at DA sets into motion a set of predetermined actions which ensure a safe landing 'somewhere'.
Vague ideas such as 'extra fuel' and 'wife and kids' just ensure that people burn valuable time thinking and not acting. From the looks of things, this Zurich diversion was enacted with little wasted time. But I wonder what plan was made on the ground in the crew room.