Strange that you would say such a thing. I think slides in LaTeX look awful. They all look the same, there is never any transition or animation (which can be very useful) and since adding images is kind of painful in LaTeX, there are usually very few images. Most of the time, LaTeX presentations are just bullet points on a semi-nice background.
Seriously, I have seen plenty of talks on plenty of conferences and events and the ones done with LaTeX always stood out as the most boring (-looking) ones.
Quite on the contrary: I am actually talking about Beamer. Maybe I was just extremely unlucky to only see really bad presentations, but I have not seen any beautiful presentation in Latex beamer and many great ones using Powerpoint or Keynote or some other tool.
I don't know what kinds of presentations you've seen, but I've seen (and made) more-than-decent presentations with it. Plus, if you have any math in your slides, neither PP nor Keynote hold a candle to LaTeX. That being said, I agree it is usually quicker to get fancy effects in either PP or Keynote.
Seriously, I have seen plenty of talks on plenty of conferences and events and the ones done with LaTeX always stood out as the most boring (-looking) ones.