I don't care whether the GM has had the spare time to learn a whole official setting well or not; I prefer for them to run custom settings to give me something unknown to Explore.
Hmmm… there definitely seems a strong correlation between "controlling personality" and "wants to be GM". I'm not so sure that GMs who want to control published settings are any less common than GMs who want to control homebrew settings.
Heck, from an alignment PoV, wouldn't it be:
Controlling: Lawful
Published settings: Lawful
Homebrew: Chaotic