TMNT as been around in four different decades. Correspond each decade to a turtle.
 

This borders a bit on being a bit OT, but a fun way to compare the four decades in which the Turtles have been around can be quite fun when referencing a turtle.

I'd say the '80s were the Michelangelo decade. Quite obvious not simply due to his slang, but it was a light-hearted, fun time.

The '90s were the Raphael decade. With trends such as Grunge, Goth, and a more "darker, serious" tone compared to the '80s, it fits itself well.

The '00s were the Leonardo decade. It was turbulent with lots of action, wars, and key government decisions, plus 24-hour news became a reality everywhere you went (maybe call it the April O'Neil decade?)

The '10s are perhaps shaping up to be the Donatello decade. With news coverage devoted to microtechnology amid problems, it will seemingly be up to the brains of people, like Donatello in order to save/advance the world!

Neat idea. I'd say I agree with your assignments.

This is an interesting idea, but I also pretty much agree with everything you stated so sadly don't have anything better to add!

Cool concept, dude. The really weird thing though is the Turtles were only created 27 years ago.

I think you just about nailed it with your analysis. Although i could see arguments for Raph and Mike to both be either 80s' or 90s'.