I think the only thing that makes me more sad than not implementing (or just plain ignoring) standards is when someone comes just that close to actually implementing standards, or even does implement some standards, and then completely ignores others, or does 90% of the work, or adds in their proprietary crap on top that makes it non-standard, and makes little babies cry.
And then there’s the whole lock-in thing, don’t get me started on that one!
Such an uncommon practice in IT, Kerberos implementation by microflop, etc. etc., which, of course, really sucks when you’re writing something like a plugin or some other sort or add-on… : (