[AtiQUOTE=IslandRed;2620598]I think it's important to not lump in "conservative" with "dirty/cynical," though.[/QUOTE]
In soccer, I think "negative" refers more to the gamesmanship that goes on with the diving, the cynical fouls, and the baiting of the other team to get players sent off. It involves trying to gain an advantage using dirty tricks. While the Italian "catenaccio" style is often associated with it, they come from two different sources. I believe the catenaccio was actually originated by the Swiss as a means for a weaker team to hold on against a stronger team, not unlike what we in the US call bunkering. Italian teams started adopting it and it spread like wildfire in the Italian pro ranks. The real negative play gained prominence in Argentina in the late 60s-early 70s, where matches became bloody affairs reflecting the political strife, and was called "antifutbol." With the Italians' penchant for importing Argentinians of Italian descent, it became the ideal place for synthesis between the two styles.
In the NFL, I would liken the negative play of the Dutch to the dirty play exhibited by the Raiders in their heyday and the Steelers of today.