That's different than an oath that is made vain (1) by having people parrot it day after day, (2) forcing it upon people who have no need for such a serious oath -- for example children in a classroom, (3) requiring it for a trivial, mundane or regular duty, (4) making an improperly worded oath -- a real oath is very carefully worded, (5) making the oath to an object or person, rather than to an ideal, or to G-d.
The Pledge of Allegiance is now and was created as a socialist indoctrination. Look it up. Francis Bellamy, Utopian Christian Socialist.
It is a bad oath in many ways. I never say it. I'll stand when it is said, and even maybe remove my hat -- but that is all. And that I only do to avoid disrupting a public meeting. If someone objected to my not saying it, I'd have to go further and refuse to stand, or remove my hat.