There aren't any amusement parks, rides, etc at the NC beaches. The only significantly populated (and I use that term lightly) areas on or near the coast would be Wilmington and Morehead City.
I grew up in FL, but I'm not a huge beach person and have only gone to the beach a couple of times while in NC. I like FL beaches better because there is more public access, public parks, etc in FL than in NC. You are no more than an hour's drive from a nice beach regardless of where you live in FL - even if you live inland, you can make a quick day-trip to the coast. You can't do that in NC if you live inland simply because the public access at the nicer beaches is very inconvenient and the distance to the nicest beaches is too far. You have to either stay at a hotel or beach house to enjoy the beaches unless you actually live on the coast.
I'll take the mountains over the dirt and bugs of the beach any day. No bikinis in the mountains, but that's what local or community swimming pools are for.