actually pretty much everyone has done this at some point. i only did the oblivion main quest 3 or 4 times tops before i just got a mod that allowed me to get rid of the amulet altogether. in new vegas you dont have to do the dam missions at all since there is no hard time limit on them. in fact this is only my third playthrough after beating all the endings and i have no intention of helping anyone this time around, nor do i have too.

Whenever I see a complaint about being able to become the leader of all the guilds, or about being able to master all skills, or about being able to do everything, I ask myself "Why would one want to?" Players make characters with no self control, no goals besides doing and having everything. Their shallow characters are barely up to the standards of a poor B movie, yet they expect the game to provide them a critically-acclaimed masterwork.

There are good restrictions for the game to enforce. Blocking you from becoming the head of two different guilds is certainly a reasonable and a fair restriction. Even if that restriction is missing, however, a character designed with even a smidge of imagination will have no reason or motivation to become the leader of both. It isn't a matter of creating imaginary restrictions, but a matter of creating real restrictions. Meaningful choices begin with meaningful reasons. If you don't want to do everything in one playthough, then don't make characters who want to do everything. Then play the character, not the system.

Important choices which entirely affect the story and world would be a major improvement. I loved Dragon Age: Origins the first time I played it, because it felt like every dialogue line I chose affected the whole world. There are dozens - nay, hundreds - of possible endings to that game, and I would like to see more freedom to choose and its consequences in Skyrim.