The LIMIT thing is a simple example why this kind of tactics doesn't buy anybody anything.
Implementing the alternate syntax from the standard is a simple matter of adding to the YACC file and recompiling. Total effort spent: one hour, maybe two if you add a test case for it.
So the only reason why MS and Oracle do that kind of thing is that they still don't understand how Open Source works.
Good for us, I'd say. :-P