Real Life doesn't work that way. All tasks are not equal. Nor will they be. Ever.
except this is not real life, its a game, yes believe it or not Vana'diel is actually created by SE and they can control weather too! and can make them very equal!
no one said they wanted to be easy (I've done fire trials) but more in line with other trials, meaning that they need to take into account weather rarity when building elemental trials, I don't think they planned ToM to have HARDCORE weathers and casual weathers...the number of kill/proc/etc objectives is where the difficulty is supposed to be.