Well, they are just plain wrong.
A number of Protestant churches say the Apostle's Creed and all say the Our Father. Each Protestant denomination holds onto certain aspects that are also shared by Catholics. That is what we should be concentrating on.
We are separated for reasons only God knows.
It will be to His Glory when we all put away our differences.
Jesus would have it no other way.
It’s explained pretty well in Revelation. There are faithful in some of the assemblies. Not so in others. One is called the whore of Babylon and those who God says are His people are urged to get out of it. Most are either Luke warm or have left their first love entirely. Those who tie themselves to a “church” will suffer the consequences that “church” suffers. Those who put their faith in Christ alone will not.