There is a lot of sense in this:
I fly around 650 sector a year and have diverted just once in the last three years, in the last 8-10 years it will be no more than a dozen times, i normally operate into major airports in a CAT3 aircraft, if operating into smaller fields with NPA and aircraft that are CAT1 only then yes the number of diverts will increase, but by and large these will be turboprop type ops with much less fuel burn in the first place! my point here is that the cost of carrying an extra 500kg for mum over the last 3 years and nearly 2000 sectors would have been far more than the cost of a divert. I could also add that even if i had an extra 5000kg on i still would have had to divert because it was 300m and the airfield was only CAT1 anyway.
Acting as a fuel tanker and carrying several 100kgs
every flight is not a sensible way of going about business with fuel suddenly being a very expensive commodity. I've diverted once in 2 years flying. The diversion would have happened even if I had been carrying even more fuel, so actually carrying extra does not do a lot for you. You should carry less and make a timely decision to divert. We must do our bit for the bottom line under current conditions- the airlines cannot afford you fuel tankering all the time when it doesn't actually achieve a great deal for you. The chances are, the extra fuel is that much more to waste before you divert anyway. I take PLOG with a significant reason to carry more required. This is even more important as the cost of fuel goes up.