I always thought it was weird that iLvs suddenly start going up by 5's at lvl 50. It seems so arbitrary.

They could just change it to go up by 1's (so i100 would be i60 and i135 would be i67 but still have the same stats as now) and it would take a lot longer for iLvs to outpace real Lvs and get up to ridiculous numbers.