Stop Adding Syllables!
Some pronunciation — and now spelling — errors have become quasi-acceptable in the language, to the point that a couple of them can even be found in the dictionary. That still doesn’t make them right.
Orientated is not a word. Orient is a verb meaning to find one’s position or direction. One can orient oneself. If one did so in the past, one oriented oneself. To be in the process of finding oneself is the act of orientation. And that’s where the confusion came in. When we take the verb and convert it to noun form, we add the suffix -ation to indicate “the act of.” Somewhere along the way, someone who didn’t know any better tried to convert the noun form back to the verb, and failed to take the whole suffix out. And now we have this pervasive problem.
Consider preventative. Another non-word. The correct form is preventive. But people get sloppy in their pronunciation, or some inadequately-educated journalist uses a word repeatedly, and we find ourselves stuck with these abominations.