That's false. We had much better options from items depending on which season you look at. In beta it was stuff like Philosopher's Stone, Catalyst, and Chalice. Then we got things like Athene's and Morello's, and Tear actually had mana regen on it.
After Riot gutted mana regen on items they made Meditation mastery better.
Runes were always an option and there was an early meta in season 1 or preseason 1 where people used mana regen runes, but then Riot nerfed the runes and buffed base mana regen on all champs to open up other rune options.
edit - Found the patch:
http://leagueoflegends.wikia.com/wiki/V1.0.0.110
"All Champions with mana had their base mana regeneration increased by 2.5 mana per 5 seconds and mana regeneration per 5 seconds per level increased by 0.2."
Mana regen has never been more restricted than it is now mostly due to items not having it anymore. If you don't bring Manaflow Band on mages you're simply at a disadvantage. It's not a matter of learning to manage it better. You drastically lower sustainability so you can be shoved in easily.