In the comments after a question, Peter Tamaroff mentioned using MathType. I am not familiar with that software. Apparently it is being blamed for such solecisms as
{ \int_{0}^{1} } { { x^{2} } }\,{ { {d}{x} } },
etc., where
\int_0^1 x^2 \, dx
would serve. I think the presence of so much of that sort of thing in math.stackexchange.com is a disservice to those who edit postings and learn how to code things in $\TeX$ and $\LaTeX$ by doing so.
Is MathType the principal source of this, or are there others?
Is the terrible practice of using \mbox{} instead of \text{} also the fault of MathType? In the normal use of $\TeX$ and $\LaTeX$, as opposed to its use in web forums, \mbox{} does not cause things to appear in text mode that would otherwise be in math mode, and serves a completely different purpose that seems inapplicable to forums on the web.
\mbox{}
does cause things to appear in text mode; anything inside the\mbox
is processed in paragraph mode, even if inside math mode (I use to use it to do cases when typing in plain-$\TeX$, before I switched over to $\LaTeX$). $\endgroup$ – Arturo Magidin Apr 28 '12 at 3:42