Protestants are considered people of the Book, not hampered by human tradition. Catholics are viewed as followers of traditions with the Bible as a secondary source of revelation. The misconception in this is that Protestants are also people of tradition. Everyone depends upon tradition, just some will admit it and others will not. An individual can read the Bible and interpret it for themselves.
Catholics have a different set of premises that direct their study of the Bible.
These basic differences place the Catholic and Protestant worlds apart even though they are opening the pages of the same book and accepting it as an authoritative revelation from God. The Catholic's position is biblical, and has been espoused from the first days of the Church. The Catholic is usually invited but their influence is curtailed since it has no place in Protestant tradition. An unwary Catholic who steps into the Protestant Bible Study usually does so with no intention of leaving the Church. They just want to study the Bible and its not being done often or well in Catholic circles.