I always used to like them, and I would have been a big defender of them from the days of FFVII - X. Now I feel like if random encounters are going to be in a game, there should be a way to manipulate encounter rates and such from the get go like Bravely Default. In most RPGs I've played, the enemies in random encounters are generally really easy for most of the game. It doesn't really add much challenge for me. They just exist to be able to grind.