Well in TNA you have wrestling, proper wrestling matches. They have many different storylines so for the most part there is a story there, there is reason for each match happening and why wrestler A doesn't like Wrestler B. Except for a few stars you have a completely different roster than WWE and the talent level is completely different even at it's most basic level. In WWE you have many guys who have only ever been trained the WWE way, they have came from one of the WWE's farming territories and their told to do everything. A lot of the young TNA talent also work indie shows, mostly to make extra money but the fact that they are working the indies too means they are also working with a wide range of wrestlers who also have different styles. That's a good thing in wrestling.
There is some wrestlers in WWE who just would not make it in TNA and yet there are TNA wrestlers who just would never make it in WWE and for completely different reasons. Even someone like Jim Ross would be no good in TNA right now. He would have a melt down on air trying to remember all the REAL names for wrestling moves, he would never cope, he's too used to 'telling stories'. The same goes for WWE wrestlers, their generic, scripted, 15 moves max, 10 minute TV match their used churning out week after week after week simply would not fly in TNA. They would get shown up in TNA.