Like all things, there is the good and the bad. The author is referring to BAD web apps that simply port desktop apps to the web.

Good web apps are ones that utilize features of web apps to enhance the application. For example

Collaborative work Easy deployment Being Viral Mobility CHEAP CHEAP CHEAP, no need to print cds.(save some trees, or petroleum)

i ran out of things for now, but i'm sure come up with more after my hot pocket.