The first is that just because something appears to be easier, doesn't make it the right tool for the job. In fact, there was probably similar excitement when the <font> tag was introduced to HTML: a quick and easy way to control presentation.
When we evangelise CSS based design, we often hear a refrain from old-school designers who claim, "but it's easier to use tables!". As it turns out, using CSS is, in many ways, easier than using nested tables and spacer .gifs. The problem is a fear of a new technology and a misplaced belief that it will be more time-consuming.
I'm seeing exactly the same attitude now being expressed by CSS designers who don't want to learn DOM scripting: it's too difficult, it will take too long.