When I see a Math lecture written in LaTeX, I immediately know that I will probably be too dumb to follow it. It's almost always a deep exposition on what the writer want to show he/she knows or how many complicated formulas they can apply rather than really try to teach me something.
Not necessarily true. If you take the score of e.g. Chopin's Ballade N.3 you'd be inclined to think sheet music is all just show off. Abstract notation takes time to parse and understand when you see it for the first time, no matter how well versed you are.
