Apparently I'm distracting (and not the good kind)

[LegoTechnic]

How is Blizz2 viable as a SMN? Does a SMN somehow buff it? It's not even viable on BLM.

It's because Ruin and Ruin II are complete and utter trash despite being SMN's primary filler ability. Blizzard is a 50 potency AoE move with 2.5 second cast, and Ruin is an 80 potency single-target spell with a 2.5 second cast (2.5 recast in case of Ruin II). If there are two or more mobs then anytime you would be casting ruin (and are not moving or focusing a target), then Blizzard II will be more damage.

Amusingly it tends to be a bottom barrel option for BLMs, but it can be quite handy for SMNs in large pulls as filler while waiting for cooldowns.