The problem is that we don't usually carry that extra ton of fuel. 2.6 ton CMR fuel for a Bristol diversion so if we arrive overhead with the 'company' fuel figure and divert to Bristol then we are down to min holding fuel of 1.5 tons at the end of an expeditious approach. At that point you will be hearing a Mayday call.
Looked at from another (hypothetical) angle, if we'd not carried the extra fuel then we'd be landing at Bristol with a MAX of 0.3 tons which is what we burn taxying from the runway to the terminal. Running out of fuel on the taxi-in is not good for publicity!!
Those 3 holds at FL100 used 1.2 tons for 12+ minutes fylying.
PS If we catch fire, immediate evacuation is not an option.
EJECT, EJECT,EJECT
PPS Wasn't aware that I'd offended in any way. No ATTITUDE intended.