@abgemacht: I'm not convinced the Premier League should demonstrate the highest quality play. I think presence in the Premier League more demonstrates a list of players who have been on the site long enough to have clawed their way to the top of a tiered system that operates only once or, at most, twice a year.
That's not a comment against the 7 players in the Premier League - I'm sure they are all high quality - but perhaps another reason disaffecting your group is the stale nature of it. The unseeded nature of the current League format saw players like myself, The Czech, barn3tt, President Eden, and goldfinger0303 being placed in the D leagues. If the leagues play twice-yearly, it will take us us within at least 2 years before we can attempt to challenge your position in the Premier League. Most of those players have a very high GR rating, Eden is running the GR challenge this month and goldfinger is "Dean" of the "School of War". It seems incredible that such highly esteemed players would have to wait 2 years before being able to challenge for the Premier League.
It's obviously a problem if getting to the top of the League seems almost impossibly restrictive for most players, despite quality. And, as you say, it's also highly destructive to the Leagues if getting to the top of the League is a wasted effort because 4/7 of the players in the Premier League are bored and unhappy with it anyway.
However, just because 4/7 of the players in the Premier League are unhappy doesn't necessarily mean that the whole thing should be reconsidered, scrapped, or replaced. It was said before that the Leagues were more popular this season than ever before - with 10 groups being played. If it is that popular then people are obviously attracted to the format and idea and, as Draugnar said, attracted to the idea of getting to know the same 6 players over 4 games with the potential to understand your opponents and use that insight over the course of the games. That being the case, why not have 2 official leagues - and create a new flagship League, with fewer, larger divisions.