Because most people feel it is the responsibility of the game designers to add difficulty/challenge to the game.
What they don't seem to understand is...this is how TES games have always been. Actually, they've been easier. In Morrowind and Oblivion, you could stand in the wilderness and jump around to level athletics. You could heal yourself over and over to get restoration to 100. You could fireball a tree...etc. At least in Skyrim you actually have to use things in combat for them to level.
In short, people have either bleached their brains of any TES experience, or they have never played a TES game. Everyone wants Fallout: Midieval edition.
In TES games, the world is so open that players can exploit almost any mechanic- alchemy, smithing, spells, etc, and become overpowered quickly. That option is there FOR A REASON. But time and time again, people want their hand held.
Which is ironic, since they're asking Bethesda to hold their hand to make the game...harder to play. Uh, kay.
Amen.
I haven't abused any skills on my characters, and I get my ass handed to me day in and day out. I've probably died more often in Skyrim than in Dark Souls, even when they both had equal play-time logged. I'm not even playing on Master, I've been on Adept since I bought the game.
It's the players responsibility to have self-control to not abuse, grind, or perform any other actions that will make their character insanely powerful. It's also their responsibility not to [censored] about being powerful when they do abuse, grind, and perform other actions to make their character insanely powerful.