I couldn't disagree with your post more. Signups have INCREASED every season by the amount of players and the amount of teams. So your FACT is incorrect
What is a pitch black picture is the ClanBase euro scene as it was dwindled to nothing over the past few years while the "North American" draft system has proven to be a better system as it is still going strong.
While I don't mind a clan system, I think that it is the reason that killed ClanBase and the European leagues. People whore up to play on the same teams and soon enough it's no fun when it's consistently the same teams that win everything because they are completely stacked. Clans drop out because they don't see a point of doing it and then it's just a ripple effect. With a draft based league, we have different teams that are evenly skilled every season. It's always a change and it's a great way to learn and meet new players.
On a side note, I don't think a clan based league would work well for the above reasons BUT I am however thinking about introducing a clan based ladder in the future. Of course it would have specific restrictions that would allow it to be more successful than ClanBase.