Why is it some carry more and its no big deal, yet others arc up in defence?
Firstly you don't know who is who on this website so some people are making it up, others are company employed stooges, and others know what they are doing.
In a jet aircraft more fuel is more weight which means a higher operating cost. If you then times that weight across an entire network it becomes a perceived expense by the accountants.
That's one of the big differences between jets and bugsmashers.
It has all been done before on here. You can't just fly around with full fuel all the time in a jet it doesn't work economically. It then becomes a juggling act over how much is enough. Unfortunately that calculation is made with a few assumptions of which none were correct in this instance.