I think overall dragons are great but personally they've lost some of their allure in recent games. For the amount of dragons there are, too many are either legendary or pseudo-legendary and I think it shows a lack of imagination on their part to keep relying on Dragons to fill the role. I think the dragon-like Pokémon are quite interesting though, the ones like Charizard and Aerodactyl.
Don't get me wrong, I train dragons and they're fun to use, I just think they're being exploited in recent games (Garchomp, Palkia, Dialga, Giratina, Hydreigon, Haxorus, Zekrom, Reshiram, Kyurem...).