They are only 5 minute games
Fouls on PES 2013 happened quite a bit, depends how you play and the formations.
These matches I've seen are all massively open because nobody has bother to check out the tactic, they have possession game and quick counter with massive high lines and teams are being opened up. Players are struggling to get to grips so they can tackle in the first place.
Too early for this, we need to judge if there are enough fouls in tighter games where both teams are at least setup properly or vs Superstar/Top Player.
Balance is the key, i liked PES 5's foul system, thing is, every game was like that. Balance.