It's been mentioned above, but with the way removal has gotten better (as has card selection to make sure you have the removal), creatures really need to be either dirt cheap, give immediate card advantage, or have some sort of built-in protection. When the only efficient ways to stop a first turn Hippie were Swords and Bolt, it was stronger. Long term card advantage isn't as strong. When I was replying above, I kind of compared it in my mind to a reverse Library of Alexandria, which wouldn't nearly be as strong today in Legacy as it would have been in the past.