Some reasons to prefer MathML: 1) Working find-in-page that lets you search equations too. 2) Ability to select, copy, paste the math bits. 3) Better acce

Some reasons to prefer MathML: 1) Working find-in-page that lets you search equations too. 2) Ability to select, copy, paste the math bits. 3) Better accessibility. LaTeX in alt text is something, but actual semantic markup would allow the UA to present things to the user the way the user wants more easily (e.g. without having to re-parse the LaTeX). 4) Ease of editing and reuse (c.f. view source). 5) Ease of styling (e.g. you can use colors to highlight parts of an equation as needed and change it dynamically; some teaching sites put this to very good use). Note that there do exist LaTeX to MathML converters, so you can still author in LaTeX if you want and export to MathML.