They are not identical though. With tax credits, if you do something, you some money back when tax season comes around. Think of it as a carrot dangling on a stick. The individual mandate is purchase this or else!
Would you want someone telling you "Hey Lindley, if you do this I'll give you this"? ...or "Do this or I punch you in the gut"!
Semantics. Either way, if you purchase insurance, you taxes are lower than if you don't.