Evangelicals, including Pentecostalists, believe that the early church was simpler, without all the ceremonialism, vestments, liturgies, etc. They would argue that many rituals etc came into early Christianity from pagan cults popular at the time - the cult of Isis, of Mithra, etc. They also feel that many of the customs of ancient Greece and Rome impacted Christianity, that the various robes, for example, are holdovers from garb at the time. Or, take celibacy. They would suggest that this certainly didn't come from Judaism, where marriage and children were just about imperative, but from some mystery religions where sex was seen as sinful, where the carnal was considered an enemy of the spiritual - influenced perhaps by Platonism etc.
More liberal Protestants would tend to argue that the church shouldn't be burdened by ancient history, that just as the early USA brought a new form of government into the world, overthrowing monarchy, so Christianity should not be influenced too much by what was practiced or written in those times before the telescope and the microscope. That's why Galileo was condemned, for example. Or consider Aquinas. He said that heresy was worse than murder, and heretics should be turned over to the civil authorities to be executed. Is this a teaching from a revered church theologian that we should honor? I don't think so.
Protestant seminaries normally have students read most of then ancient fathers, like Origen, Irenaeus, St. Clement of Alexandria, St. Augustine of course, and others. And their writings are valued. But they do not occupy the same place among Protestants as among Catholics.
As for church history itself, it is full of wonderful events, true, but it also is full of actions (religious wars, crusades, heresy hunts, inquisition, bad popes, etc) that should make us all blush. Such travesties have given rise to recent books by Hitchens, Dawkins, Harris, etc. whose united theme has been that religion is the cause of much of the evils of history - and today.
