I don't see why people need to swear an oath on anything in the first place.
Maybe its just my commitment issues, but i feel one should not make such absolute statements, if one is unable to predict future events, and how one might react.
Fact is, we'd all like to think that we'll "do the right thing" when the shit hits the fan, but who really knows what we'll do until it actually happens.
What are the consequences of breaking such an oath anyway? If someone enters a job, or position, where taking an oath is unnecessary, and messes up, they are either disciplined or fired. I'd expect the same would occur in a sworn in position as well.
"The good Christian should beware the mathematician and all those who make empty prophecies. The danger already exists that the mathematicians have made a covenant with the devil to darken the spirit and to confine man in the bonds of hell." - St. Augustine