I think the term "Protestantism" is the issue, since it may be widely interpreted to mean any church that is not expressly Catholic or Orthodox, or narrowly interpreted to mean the 20th-century mainstream Protestant churches, namely Episcopalian, Methodist, Presbyterian and Lutheran, and some of the smaller sects that merged with them (such as Evangelical United Brethren, which merged with Methodist Episcopal to form the UMC). Those old-time "mainstream" churches have gone down the slippery slope with feminism and homosexuality.
"Protestant" has old-time associations with "protesting" Catholicism. Many of the later-forming "evangelical" or "pentacostal" denominations in the U.S., as well as the SBC, are striving to remain Biblically traditional; although many of them also have corruptions of the Word or what I would call insufficient scholarship of the intentions of the Apostles and the early church.
I think most of the “corruptions” are of such minimal consequence that they fall under the “don’t get into useless disputations” clause that the apostle Paul warned us not to fall into.
Christ is God in flesh, born of the virgin Mary, killed, resurrected and now is an advocate for us with the Father! He died to cleanse us from sin and to restore us to fellowship with the Father. Though the serpent bruised his heel, Christ has crushed the serpent’s head! Christ delivered the truth of himself and the gospel to the apostles as he was the chief cornerstone thru which the apostles built the Church via the Holy Spirit. Christ will again come back to destroy the works of the devil completely and to claim his own, both those then living, and those dead in his name. We are urged to confess Christ with our mouths and to believe that God has raised him from the dead in our hearts in order to be saved; and then, having done so, to be baptized in his name. We are also urged to preach the gospel to every creature, where we may...in our immediate surroundings and unto the far flung parts of the Earth!
There lies the basic Orthodoxy of the faith,,,more or less as any simple man can understand it! The rest is semantics and slantings of the various teachers and preachers, most of which are pretty decent, no matter what denominational persuasion.