The thing about these exploits is, you don't stumble upon them or trip over them playing the game. You have to grind them out while playing the game. So, if you use exploits to power level your character or a skill, then you only have yourself to blame or thank for this.
Are you kidding me? Let's look at the mentioned "exploits" which are in fact not exploits at all.
Restoration. It's possible to use a mixture of fast healing and equilibrium to create a constant circle of magicka replenishment while devouring health, while at the same time increasing you're restoration skill at a godly speed. one could go from a level 10 to a level 100 in no more than 30-45 min.
Using Equilibrium together with a healing spell is pretty intuitive and natural. If you are playing as a mage through the college quests and have no yet found the awesomness that is enchanting then this will be a staple of your magicka management.
2. Conjuration. This is definetly an exploit because the fastest way to increase this skill doesn't even make sense.. sure you could spam the conjure ______ spell while in combat countless times, however it's also possible to cast the soul trap spell on a DEAD person... allowing you to max your conjuration skill in 30 mins or less. ( I tried this last night.)
At some point you're going to cast a soul trap late and hit a corpse and you'll get a skill up. At that point it's reasonable to assume a light bulb would turn on in your head and you'd at least test it out...
3. Illusion. This is an even faster level increase than conjuration. and the most simple because you can do it anywhere, even on the go.. just spam Muffle. once again 30 mins or less.
Walking around trying to be quiet? Cast muffle... get skill up. HMMMMMMMM... light bulb on.
4. Enchanting. I wouldnt techniquely call this an exploit however it was poorly designed and leaves no challenge to leveling up. Collect as many clothing items as possible, and enchant with as many soul gems you can obtain.. you go up a level every 5 to 8 enchants I believe.. I went almost the entire game (i'm a level 60) without touching enchanting. but after all the soul gems I had collected I was able to increase my enchanting skill to 100 in a little over a half hour. This shouldn't of been possible.
The only way to level up enchanting is to ... enchant things, it is quite obvious doing as much enchanting as possible is your road to enchanting mastery.
5. Smithing. I'm sure that all of you know this one by now.. so I won't even get into it.
Similar to enchanting you improve your smithing by smithing.
As you can see all of these can and will be figured out simply by playing the game. It's rather odd to assume that a player would be so dumb as to completely miss these when they are basically punching you in the mouth the entire game.