Semantics
One could argue that the entire purpose of this thread is to discuss houserule suggestions, but anyhoo...
I would definately suggest that any GM who feels they need to restrict spell acquisition make it clear up front what those restrictions are, since being told on a case by case basis that you can't have something can feel rather arbitrary. Additionally, if you have not approached the problem in a systematic way prior to a player asking for the spell, it is unlikely that you are doing something balancing. Few things feel less fair then an on the fly 'you can't have that' that doesn't have a well thought out explaination. Another problem is that some builds rely on the availability of specific spells or at least don't work well without them, and if you have been building toward something and are told at the last minute that you can't have it, it would be understandably frustrating.
I am currently in a game that heavily restricts what spells a wizard or sorcerer can cast, roughly, all wizards are restricted one of 6 six 'wizard schools', each of is restricted to (roughly) 3 schools of spells plus some universal ones. Sorcerers can only get spells from the PHB except by spending a feat per spell from another source but suffer no school restrictions.
Additionally, Cleric spellcasting is a full round action for all spells that are not healing or domain spells.
The GM has stated that he is doing this to reduce that power of spell casters in the game.
No one at the complains since we know what the rules are ahead of time. No one is playing a arcane spellcaster either.
I was in another game where access to teleportation magic longer range then dimension door was heavily restricted, and acquiring it carried certain risks due to the likely attention of a very power NPC.
He specifically wanted it to take time to travel from place to place as part of the campaign. Never have I gotten so much use out of phantom steed.
Again, this was all fine with the players because it was known ahead of time.
The gist of all of this is that the GM sets the restrictions and the players will respond by playing what they feel will be fun within that framework. That said, there will still be people who play characters that are more powerful then others, it will just change what that is.