In a word, “expectations”. There is nothing wrong with the moniker itself, but when used as if it were a thing-in-itself, as something concrete, it inevitably becomes misleading. This is not something to solely blame on marketing hype – people crave simple labels, marketers are just accommodating us. We need to take a little responsibility for asking what such labels really mean. When forced to reduce Web 2.0 to something real, you end up with AJAX. There is also nothing wrong with AJAX or its components. The problem is overestimating what it can do for us.
Bill Thompson’s post “Web 2.0 and Tim O’Reilly as Marshal Tito” yesterday on The Register’s Developer site, is perhaps a little overstated, but is useful reading for VCs and IT strategists. Here’s a sample: