You're kidding, right?
I think there are some things that both Protestants and Roman Catholics agree on:
1. God created the heavens and the earth.
2. Man is, because of sin, in need of redemption.
4. God is triune -- three persons in one Godhead.
On many other things, you (a Roman Catholic) and I (a Protestant) can disagree.
But I would never call another person who believes in those things "silly". Nor would I suggest to another person who believes in those things that he or she is being "wicked" and "disobedient" because he or she failed to adhere to some doctrine or another.
The reason I would not do this has nothing to do with my own sense of manners and how one ought to treat other people.
Rather, it has to do with something Jesus prayed for --"that they might be one" [John 17:11].
I'm not sure, but I think divisive statements towards other believers do not contribute to what Jesus prayed for.