They have the 40 minutes rule for reasons of efficiency, the policy is clearly stated so I don't see why you were upset - you should arrive earlier. As for the fog, not much Ryanair can do about that I'm afraid.
I'll agree with you on the fog, a little. In the US, if a flight gets delayed for Weather, the airline still gets you home somehow. Ryan Air offered to refund my airfare only.
As for leaving earlier, I read this statement as "it was your fault you were late, you should have left earlier, and you deserve what you got."
I've flown Ryan Air many many times and I knew the airport well. I also knew when to leave to get there on time. Unfortunately the parking lot was torn up from construction, making the nearby spaces filled, and it took me a long time to find the poorly labeled alternate lot.
At the time I was annoyed because I felt I had done what I was supposed to do and there was nothing stopping them from providing the service. i.e. the security line was non-existent and I was there 35 minutes before take off.
The policy is what it is, but I think what really got to me the most then (and thanks to you reminding me) is the presumption that I did something wrong by not anticipating the construction and that I deserved to be punished by strict adherence to the policy.
In the US, we consider this very poor customer service.
