It does have the distinction of being what is probably the most powerful individual card in Guilds of Ravnica limited, contending with fellow surveillor Doom Whisperer and card advantage engine Experimental Frenzy, not to mention Niv-Mizzet
Whether players liked the cards or not, they generally agreed that they didnt hit the right vibe for Magic: The Gathering
I have a more detailed explanation of these in the introduction of my Graveyard Overdrive blog
This mainly affects the lands you'll be playing (as well as Jorn himself), and will give you double the amount of mana to use on each turn
So, why worry about how to block it or how much damage its going to do when you can simply destroy it instead
Birds of Paradise, Budoka Gardener, and Lotus Cobra essentially complete the early-game acceleration