Destro benefits from enchanted gear, potions and poison. So we get 2 skill that let our dmg go up and 1 skill that makes us spam attacks without mercy. None crafting skills are needed to achieve this. Enchanted gear for nearly no mana cost can be found or bought ingame, the hardest hitting weakness poison can be found or bought ingame, and destro dmg pots can be bought or found ingame but not as good as hand crafted ones ( still at least half as good ).
If your only playing destro mage you wont level anything except destro tree. Sneaking ? why would you sneak if your such a badass in the first place. Lockpicking ? Why would you not use the Stone buff or your companion for opening lock. Pickpocket ? Why would you need to steal anything if your dont want to. Speach ? Yeah its gonna level when you sell loot but are you going to become a pack mule and loot everything there is to loot in game :sadvaultboy:
Even with this I could still level all my other skills to 100 and reach lvl 81 and never perk anything other than destro tree and be able to dish out good dmg. When the situation gets hairy I can just use a dmg pot and If im against something really powerfull I can just add a poison.
I never said that destro is bad at higher levels I only agreed with the statment that if your just using destro skills you wont level that high to even notice destro becoming weak without using other means of dmg boosting.
Seams we just misunderstood the situation.