Got it. I thought you were comparing to other software tools.
I'm a big fan of chalk talks for anything mathematical. I find it hard to stay engaged with slides, even if the presenter uses tricks like revealing one step at a time, annotations, etc.
Powerpoint is optimized for marketing and not much else. It exists because of two reasons:
1) Most people actively suck at presenting something. Forcing them to put their presentation in Powerpoint-standard forces some level of organization on them.
2) A lot of business presentation IS marketing--and Powerpoint is fine for that.
The problem is that a lot of technical communication really doesn't fit into Powerpoint-standard (see: space-shuttle disasters for example). The problem is that now nobody knows how to do anything else and never even thinks about doing anything else.