Is the full tank of fuel comment not speculation as well, though? I find it difficult to see how you could know how much fuel was being pumped, unless airport fuel pumps are like the ones you get at Tesco and you saw the numbers rising!
But who's to say they weren't taking on fuel thinking they might get up and away towards the original destination but have to circle or divert again should conditions worsen? I can speculate as well.
All things considered, it wasn't ideal or as planned but BA did get you to your destination. And the weather is outside their control! I have to say I struggle with the idea of describing this as 'bad' treatment by BA.
Edit: On second thoughts, I can agree that not having a drink for 4+ hours is bad and would have expected the bus to have say bottles of water available, but I'm still not convinced on the other points.