So people choose to give their enemies more health then complain that their spells aren't killing the enemy as quick as they want it to?
Terrible argument. People want to make the game more difficult, but not difficult in an arbitrary sense where it just takes longer to kill things, but you're killing them in the same way (spamming one spell over and over). We want the difficulty slider to make it necessary to use spells strategically, by making the encounters different than they would normally be, and making enemies more difficult by making them smarter, giving them extra abilities, etc. Not just increasing their health and damage.
The game as is doesn't provide enough buff type spells or protective spells (there aren't even heal over time spells . . . ) for this to work, unfortunately.
Also, since you can carry an unlimited number of potions with you and chug as many as you want as often as you want (and since your health/mana recharge very quickly after an encounter), increasing the difficulty in Skyrim just makes play more tedious, but not really more challenging.
I don't use potions gratuitously (or really even very often) on master. Not to make it harder, but because I'm lazy, and because there's rarely a situation where I actually need some.
The game is too easy on master, and if you have conjuration you really don't ever
need, to cast a destruction spell.