lol....yeah do math but forget half the equation. You forgot time.
let me explain with numbers i just witnessed on my alt. ( post nerf less people doing them but still use same time table)
before nerf ( for level 90+)= 300k per zone. you did 2 zones. 600k ( pretty much 1 level). 1 zone was 20 min even with hord/allaince trouble. + 5 min travel time. that was about 45 min to do 1 level. ( many people where doing it to boost their alts).
so 2 zones= 600k for 45 min= 13k xp per min!!!!
post nerf = 100k per zone. you need 6 zones for 600k ( 1 level). 1 zone takes 20 min, 5 times 5 min travel between zones.
so 6x 20 min = 120 min + (5 times 5min)= 145 min for the same xp.
so
so 2 zones= 600k for 45 min= 13k xp per min!!!!
so 6 zones= 600k for 145 min= 4k xp per min!!!!
so thats 3 times LESS xp per min for doing invasions.
i know math is hard.