I simply don't think that's true. The demonstrators in Seattle are entitled to their opinions. But they don't represent public opinion at large. Moreover, public opinion in developing countries has swung massively towards liberalisation since the mid-1980s. A fourth factor is the need for leadership and flexibility.
Some people blame individuals.
Others think the problem is more deep-seated. The end of the Cold War has reduced the urgency of taking tough decisions to strengthen the world trading system. Moreover, while the United States is still a hegemonic power in international monetary policy, it no longer is in international trade. The European Union is the United States' equal, and their interests, as well as their view of the interests of the multilateral system, often diverge. Moreover, developing countries, though by no means a unified block, are increasingly assertive too.