Pointed Discussion

A decent lockdown effect against opponents running mono-green or other limited effects, but holds a significant drawback for yourself as well, while your opponent can still draw and plan to eventually overtake this effect while your playing field remains stagnant.

Stormtide Leviathan? In white enchantment form?

There are plenty of other ways to get cards into your hand such that the drawback is almost negligible for the effect. Combo with Humility and now you can't be attacked pretty much at all.

Nice card against mill decks.

With a Howling Mine or two in play, Island Sanctuary makes mill a viable option. Your opponent will be outdrawing you each turn, but with a little control (via Stasis or Winter Orb) and a Black Vise, you can use that to your advantage. Combine with Mystic Decree for even more fun.