While it wont prevent all their creatures from untapping, it holds off the stronger creatures while its on the field
While not a mono green deck, I have a Simic (blue/green) Sea Monster deck that I play this card in
One your mana was doubled there were any number of ways to start generating massive card advantage and take over the game in short order, with Wrath of God serving as the four-drop to lead into the Wake and Mirari itself, which was usually the way things ended
He still gets all of the goodies that black and green together gives you, but by giving up Rakdoss Return and the red removal he gets access to one of the most powerful cards in Standard: Elspeth, Suns Champion
Then there's the question of multiple layering replacement effects with Scales + Gatta and Luzzu
Graded Population Report: Cloud Strife #42 Visualize the distrbution of grades in the chart