"Gen 2 and legendaries: please explain to someone with no Pokemon background"

#PokemonGO: First a little context: I'm 33, was a bit out of the targetted audience when the games and tv show came out, so never played any of the previous games, and barely glitched some episodes of the tv show while my little brother was watching.I knew about the franchise, knew a few characters/pokemons names, and got the main plot from the lyrics of the opening song. But that's about it.In the last few days I was reading some people arguing about the release of gen 2 pokemons and legendaries. Basically some are saying it doesn't make sense to release gen 2 before legendaries, and others are saying it's not a problem at all.Could someone please try to explain in a neutral way why both sides think they're right and the other is wrong? I feel like I'm missing something here.Thanks!PS: There are probably enough controversial posts on the topic so no need to turn this one into it.edit: minor text fixes via /r/TheSilphRoad http://ift.tt/2gV4PLV