I agree most power point presentations are a waste of time. Most of them have very little content. Most of them suck big time. Where I disagree is, blaming the tool for the sins of the tool wielder.
There are, however, good and bad tools. Powerpoint is a bad tool, and it is not by accident that almost all presentations suck, and it's not because everyone is bad at it. The whole program is focussed on being flashy, not on content. There's 50 buttons and options for animations, colour, flash, bling, look-a-three-headed-monkey - and maybe 5 buttons for content. There are plenty of examples included for different visual styles, but none for different methods of content presentation.
And, like almost all Microsoft products, it wants to be everything to everyone. So it doesn't restrict you, but every designer knows that restrictions are great. You can put 9pt fonts on a Powerpoint slide. For 99% of the usage cases, that is an absolutely abysmal idea. But it leads to people misappropriating habits from Word for Powerpoint - if your content doesn't fit, shrink the font size. Ugh.