This is half true. Indeed, currently European/NA players play quite "standard" at tournaments, avoiding rushes and "all-in" strategies. The Koreans, however, at GSL have shown that they're neither afraid nor hesitant to do so.
In the GSL (the largest SC2 tournament) there have been quite a few all-in rushes. Usually one player doesn't like his chances on the map, race matchup, or he feels he is inferior to the other player so he all-ins in an attempt to pick up an unlikely victory.
edit: GSL, not ESL.