Some people take it waayyy to seriously, in that they'll go too far in changing everything without realizing that they're taking away from the quality of the hack. Graphics, for instance, are altered sooo much, and so much effort is put into them, yet the entire point of putting them in (to make the gameplay look better) is forgotten about.
But some people also take ROM hacking too lightheartedly, and will create a hack without any knowledge of how a game's supposed to be. For example, the basic structure of a Pokémon map is often overlooked, such as how trees are placed.
I'd say a fine line between the two (I would consider calling it a 'casual' developer) would be the best state for being a ROM hacker. Having a lot of knowledge about game mechanics, but not putting every ounce of effort and time into the game so that maps and scripts are rushed, should turn out to be a hack worthy of the Hall of Fame.
