It is likely that most reject this reasoning due to a theological bias. But, as can be seen below, Jehovah's Witnesses weren't the first to reason that Jesus is Michael the Archangel:
"In a number of passages we read of an angel who is superior to the six angels of God's inner council, and who is regularly described as "most venerable", "holy", and "glorious". This angel is given the name of Michael, and the conclusion is difficult to escape that Hermas saw in him the Son of God and equated him with the archangel Michael. Both, for example, are invested with supreme power over the people of God; both pronounce judgment on the faithful; and both hand sinners over to the angel of repentance to reform them. ... The evidence to be collected from the Apostolic Fathers is meagre, and tantalizingly inconclusive. There is evidence also, as we observed in the preceding paragraph, of attempts to interpret Christ as a sort of supreme angel; here the influence of Jewish angelology is discernible." - Early Christian Doctrines, by JND Kelly, pp 94, 95)
In The International Standard Bible Encyclopedia, John A. Lees says:
"The earlier Protestant scholars usually identified Michael with the preincarnate Christ, finding support for their view, not only in the juxtaposition of the "child" and the archangel in Rev 12, but also in the attributes ascribed to him in Dnl (for a full discussion see Hengstenberg, Offenbarung, I, 611-22, and an interesting survey in English by Dr. Douglas in Fairbairn's B{ible} D{ictionary}." (1930, Vol. III), p. 2048 (and in Vol. IV, pp. 238-241 of Zondervan Publishing's 1957 reprint.)
"ARCHANGEL. This word is only twice used in the Bible, 1 Thess. 4:16; Jude 9. In the last passage it is applied to Michael, who, in Dan. 10:13,21; 12:1, is described as having a special charge of the Jewish Nation, and in Rev. 12:7-9 as the leader of an angelic army. So exalted are the position and offices ascribed to Michael, that many think the Messiah is meant." - International Bible Dictionary, published by Logos International, Plainfield, New Jersey, p. 35.
Protestant Reformer John Calvin said regarding "Michael" in its occurrence at Daniel 12:1:
"I embrace the opinion of those who refer this to the person of Christ, because it suits the subject best to represent him as standing forward for the defense of his elect people." - J. Calvin, Commentaries On The Book Of The Prophet Daniel, trans. T. Myers (Grand Rapids: Baker Book House, 1979), vol. 2 p. 369.
John Wesley's Note on the Whole Bible:
Daniel Chapter 10
13. Withstood me; God suffered the wicked counsels of Cambyses to take place awhile; but Daniel by his prayers, and the angel by his power, overcame him at last: and this very thing laid a foundation of the ruin of the Persian monarchies. Michael; Michael here is commonly supposed to mean Christ. I remained; To counter-work their designs against the people of God
21. Michael; Christ alone is the protector of his church, when all the princes of the earth desert or oppose it.
C. H. Spurgeon from "Mornings and Evenings":
"To whom do we owe all this? Let the Lord Jesus Christ be for ever endeared to us, for through Him we are made to sit in heavenly places far above principalities and powers. He it is whose camp is round about them that fear Him; He is the true Michael whose foot is upon the dragon. All hail, Jesus! thou Angel of Jehovah's presence, to Thee this family offers its morning vows."
For much more, see the category:
Archangel
This website examines the unscriptural and pagan history of the Trinity Doctrine - often through the admissions from Trinitarian's own sources. This site also provides comprehensive research that exposes the false reasoning behind almost every Trinity 'proof-text'. Subjects can be found through the Indexes, Links or the Search Box below.