Is going to seminary really necessary?

Seminaries were established to prepare men for the ministry. Men because only men could be lawfully ordained. Many men saw seminary as a necessary path towards their entry into the ministry.

However, it has come to my attention that many seminaries (even Evangelical ones) are teaching seminarians to doubt the Bible. Evangelical pastors graduating from these seminaries now firmly think that the traditional conclusion of St. Mark's Gospel (Mark 16:9-20) and the Pericope Adultarae (John 7:53-8:11) are not part of Scriptures. Even famous pastors such as John MacArthur and John Piper doubt Mark 16:9-20 and John 7:53-8:11 respectively. 

The seminarians are also taught to reject the Textus Receptus (TR) - the traditional Greek New Testament text handed down by Christians from generation to generation throughout the centuries, and to accept and trust the false Arian Modern Critical Text (MCT) - a text rejected by ancient Christians and effectively disappeared for 1,400 years but promoted by unbelievers since the 19th century. 

In addition, the seminaries appear to encourage antipathy towards the Authorised Version (KJV) - the faithful and most accurate English translation of the Word of God. Is this one reason why modern Evangelical pastors keep complaining about the 'old English' of the KJV?

The seminaries are promoting scholarship done by unbelievers who deny the truth, infallibility, and Divine Preservation of the Word of God. It seems that seminarians now trust in some academic methods (also invented by unbelievers), and have no problem accepting theological scholarship done by unbelievers.

Is this why many Evangelical churches are increasingly becoming more liberal?

More importantly, if seminaries are teaching men to doubt the Word of God and to trust the works of unbelievers, is going to seminary really necessary for men who wish to enter into the ministry?