Having less options can sometimes make the gaming experience more enjoyable and decrease the complexity of a game system. To that end, I usually do two things: Look for campaign settings and supplements that stay very close to the core rules of their chosen system and shy away from changing rules during game play without careful consideration.
I have seen a lot of campaign books and supplements that believe that page count is equivalent to quality work. I have seen several GM's that buy into that idea and bring into their games these extremely large books with complicated ill-conceived options that do nothing but confuse their players.
Most of those books have one thing in common: They change or add a lot of options to the core rules of their game systems.
Those changes add an extra layer of options that allow the content creators to further pursue their creative insights. They also make the system more complex and in most cases, unbalanced. An unbalanced game system creates more work for the GM, and it can, many times, frustrate the players.
The work for the GM starts at trying to figure out the correct power level of the characters when using these new options. Once that is established, the challenge rating has to be modified to match that level. That is usually accomplished by tweaking monsters or adjusting the skill checks.
To the players, these new options are both a blessing and a curse. As a blessing, their characters can have some really neat options available to them, allowing them to run wild with their imaginations. While as a curse, they may fell punished for not fully utilizing the options to mix/max their characters.
If the players start feeling punished, they will become frustrated and may even start resenting the GM. They may see their characters as worthless and want to change them. Be it by marking a new character or worse, changing the rules on the fly.
Changing the rules on the fly requires careful consideration, usually more than what is available to the GM just before a session. I usually tend to shy away from those types of changes as well, since, like any other changes, they tend to have bad consequences for just about everyone else at the table.
Fewer options can make for an enjoyable game for both players and GM. Carefully choosing settings and supplements, and avoiding rules changes on the fly can help everyone achieve that goal.