>>23504560trying to create a metagame as diverse as pokemon cannot be done very efficiently, especially without GF's blessing.
Establishing clauses and bans that are possibly only in effect for a few weeks or months eventually gets very confusing to those who aren't updated often on the news of a constantly changing game. (X pokemon gets banned to Y tier, another vote 5 months later votes it back to Z tier).
Trying to organize pokemon into certain tiers for play is an extremely difficult task simply because Game Freak never intended pokemon to only be viable against a very limited set of pokemon.
To Smogon's credit this has done well to make people's favorite pokemon with low stats not get absolutely murdered by a Kyogre or something. the take home is just that laying out solid lines for tiers is extremely difficult, and changes every day, going back to the constant updating deal.
I would say the biggest deal is not creating a welcoming atmosphere and not keeping a handle of some of their mods and admins. They've create a huge "I win, you fucking suck" attitude towards a children's video game that will be tough to scrape out and actually create a sense of decent sportsmanship around.
Also the mod problems are due to recent events, but pedos and such weren't unheard of in the past either.