The Ninja 250 is the classic bike to learn on. People buy them, learn to ride, feel inadequate when they see someone on a faster bike, and then sell them to 'move up'. Nothing wrong with that.
My second motorcycle was a Ninja 250. My 4th (and current) is also a Ninja 250. I'm a practical person, and I don't have anything to prove. I don't want to go 160 mph. I'm quite content cruising at the posted speed limit (well usually), and keeping all the extra money in my pocket.