In order of importance:
1. Unequal Representation: While the 2009 edition saw the participation of the top two teams of England's domestic t20 league, this edition was devoid of an English team, for reasons of a clash with the domestic circuit. Mind that England are the international T20 champions of the year, and are without a domestic team representing them. The 2009 edition was meanwhile without a team form New Zealand, for whom the Central Districts Stags got a spot this time around.
2. Infancy of domestic T20 leagues: Though the Indian Premier League is nearing is 4th edition, T20 leagues elsewhere, with the exception of England (which makes it even more questionable to be without an English team), are still in their formative stages. The Australian T20 Bash has been successful, but it's younger even than the IPL. Overall the leagues are more or less haphazard, which is why this edition was without previous finalists, New South Wales Blues and Trinidad&Tobago. Such a tournament should pit teams from well established leagues with one another, as happens in Football's UEFA Champion's League, on which ACLT20 is idealised.
3. Errant team compositions: Many players are involved with two teams, that end up qualifying for the tournament. Case in point is West Indian Kieron Pollard. With Trinidad&Tobago in the 2009 edition, with Mumbai Indians in IPL2010, with South Australia Redbacks in T20 Bash and opted for Mumbai Indians this tournament. A team cannot be expected to let a player be a double agent ( a triple-agent in Pollard's case). A player cannot be involved with more than one team going into a tournament. Uncertainties don't bear well for any of the teams. With the same player being involved in more than one domestic league is acceptable, as his presence in a team doesn't affect the prospects of others in the same domestic league. But when the same player has helped two teams enter a tournament, as in this case, there is a conflict. Pay-offs are arranged in this case, but that is more a job of hushing up dissent.
4. Multiple commitments: For example, Kevin Pietersen of Royal Challenger's Bangalore. ACLT20 is an international event going by the different geographies of the participants. KP is now playing at County. Even had he not, he would've still been a part of the national team in the ODI series vs Pakistan and thus would have missed ACLT20. Staging this event in clash with the ODI series or any other International fixtures will unfailingly make a player fore-go the tournament. It is perhaps an easy excuse to do without domestic English teams, and given that there aren't any Englishmen in any IPL team, the effect wasn't felt in this case. Now if future ACLT20s clash with fixtures for Australia or South Africa, IPL teams, and domestic Australian and South African teams will take a hit and be deprived of quality. There is the reasoning that there is no better space in the calendar - but i say, find space that affects none. Omissions of teams or players is just a very bad idea for getting away.
5. Wait till IPL's new auction: With all IPL teams to undergo a major reshuffle, in wake of the two new teams, the next ACLT20, may very well be without any of the 3 IPL teams featuring now. This is why it would have been best to wait for all leagues around the take shape before unveiling this. When a previous finalist doesn't feature, it is more akin to a ramp for new teams to show case themselves rather than a 'Champion's league'
