TMNT Logic
 

Not sure if this has been asked before but why do all turtles gotta train their entire life to be competent in fighting whereas mutant villains come fight-ready upon mutating?

The turtles are trained martial artists, stealth specialists and survivalists. They can more then just fight, they have tactic, team work etc.

That aside, anyone can fight, throw a punch, kick, scratch or bite. Most creatures can. And the turtles do need adversaries to overcome.

hmm
 

It's been said before anybody can fight and the more skilled villains you see in the show are usually from another dimension or have had years of training themselves.

In the real world, many train all their life, whether it be an athlete, actor, politician, or almost any other job in order to strive that they've known what their doing and understand the only thing that matters. That's why the villians are evil since they just want that "get rich quick" scheme of breaking a law by trusting those who never had any goodwill and while they can capture anyone who doesn't know the TMNT-style logic, sooner or later the masters can figure out any problem with the proper skills. Those villains tend to be either villian of the week or can easily be taken down such as Bebop/Rocksteady. Now the more masterful villians who train have the best shot of defeating our heroes, and a Lord Krang, Shredder, or even Karai can show what they need to succeed against their rivals.

The Turtles basically had Splinter as the first creature that they've met, and being a surrogate father in away, passed down his ultimate mission in which he had trained most, if not all of his life to his own students, and by doing so just wanted to be safe from any intruders.

villains lack discipline... you dont see shredder having bebop and rocksteady doing backflips for punishment.