I don't think, that naturalize is good choice in constructed, where one card for three is a deal, that your opponent would usually wish to make himself. As a druid you should have enough big creatures and spells to fight your enemy's big creatures and even legendaries. And if you make 2 for 1 deal against them, it would still be better than naturalize. Keepers of the Grove and Tinkmaster is the cards you rather need, that could be used as silence against tricky minions.
Naturalize could be useful in arena, where you didn't have much options and where chances for your opponent to draw something useful are much lower. Also naturalize could be rather fun to use, when your opponent have 8+ cards or under a threat to be killed by fatigue, but it very situational.