Re: XSLT Hello World

Here "misused" doesn't mean "will give the wrong answer most of the
time."  Here "misused" means "should be avoided because
A. There is a better way to do it.
B. Occasionally in some contexts and with some inputs, it will give
unexpected/undesirable results."

Exactly.

The same goes for !=

just _always_ gives unexpected and undesirable results, except sometimes
by chance when you get lucky and you're in a context when it means not(a=b).