I think the element of surprise is key to this being a great blocker, but also the fact cube designers are much more likely to buy a creature on basis of it's power than it's toughness yes? Being able to kill one thing and chump another is also incredibly useful.
I don't really know why people don't think this will be a fine attacker. decks consistently able to make 5-6 tokens with spells have always gone into the next few turns with a huge upper hand, we cant forget this card is an instant and very capable of taking advantage of a lack of blockers to devestate a planeswalker or life total. I expect there will be many turns that I spend six mana on this to finish off a planeswalker with one blocker left hanging out. I've also lost tonnes of games I thought I'd win to a a top deck'd
Supply / Demand or
Decree of Justice or things like
beacon of creation or
symbol status.
Then you can't forget each token is an actual freaking card. The sort of thing that benefits from all the silly creature synergies people would care to play. Think how much better this card gets with your trumpet blasts guys! Your Blasting station just turned it into a plaguewind+. This card feeds delve, triggers spells matter garbage and lets you translate all your mana, or any of your mana to board position! It's sweet! So what if it's not good at blocking surrak on curve? I can block him for a million turns or I can just use my freaking journey to nowhere on that guy and use my tokens for something they are more suited to! They can freaking attack, and what are ya gonna do, not attack me so you can potentially take one of my stupid tokens a turn through blockin? Puuuuhlease.
Also I dunno if I talked about this yet but you know what encourages overexertion? Freakin any number of tokens. Gonna make a one card quagmire so you have to play your hand and then WHAM!
Terminus Baby!
I'm a ramblin man! Anyway this card can fuck up an entire boardstate when you play it mid / late game and thats part of the reason I think it's a sweet blocka.
Also please
Bootster, I gotta know more about what your control decks seem like because if you aint into reactive stuff like counterspells or eot removal and it's already very difficult for cube decks at any given time to be built around having removal in hand consistently I am having trouble differentiating a control deck from a midrange deck that plays a lil more card drawing and maybe two sweepers instead of one omg.