Everyone seems to agree that this has been a poor Copa America, and the reasons are not too difficult to find, but some of them can’t be fixed.
First of all, inviting Costa Rica and Mexico, then telling them to use their U-22 teams can’t have helped the quality.
Meanwhile, the tournament format means teams can meander through the group stage at far less than their best. I think inviting 6 teams, to bring the total number up to 16, is the right solution.
In general, though the higher the stakes, and better the teams, the more defensive the games are. With the underdogs so close to the level of the favorites in South America, they have enough talent to stop them from scoring. Meanwhile, some of the world’s best coaches are coming to South America, and making sure their teams don’t lose.
The Copa America used to be played every two years, and became less and less important because of the sheer number of fixtures. It was decided the tournament would be used as the main competitive test before World Cup qualifying, which is quite a marathon in CONMEBOL, so the Copa may have to get used to teams focusing on the World Cup.
The answer to “what happened to Brazil and Argentina?” is partly just a focus on the World Cup, and not enough time yet for the coaches to change things. Remember that if either had won that penalty shootout, they would have been favorites to win the rest of the tournament.
I think Argentina took a huge step back in firing Sergio Batista, because their next coach will have even less time to work with the team, and there have been many bright spots to Batista’s first year in charge, especially the victories over Spain and Brazil.
Anyways, don’t expect a great tournament in 2015, though you could see a post-match brawl and a few coaches sacked.