Maybe. But maybe the so called tier 3 and 4 teams are better than ever and are making it hard for the big boys? Except Qatar offcourse. Japan 2 Germany 1, S Arabia 2 Argentina 1, Morocco and the USA having a 50/50 draw against Croatia and England. In all honesty when Spain trashes poor Costa Rica 7 0 its more a reflection of the poor quality of the losing side than the so called quality of Spain. Cameroon and Serbia had a great game as well. In conclusion, no I dont think the quality of the WC has declined.
Morocco beating Belgium alomst sliped my mind.