It is because of wrong understanding of the scriptures by JW's.
But heaven forbid there could be wrong understanding of the scriptures by Christendom, formulated exactly when an apostasy was foretold eh?
What a co-incidence!
You take so much for granted. That is the only Christianity you have ever known....the interesting thing is, that Jesus says he NEVER KNEW the ones he rejects at the judgment time. (Matt 7:21-23) That means that the Christianity they claim to follow is not, and never has been recognized by him.
Jesus is a separate person;
Yes, Jesus is a separate person to Jehovah. Jesus called his Father "the only true God" without including himself. (John 17:3) He identified himself as one sent forth by his Father. He only ever called himself "God's son"....he never once said he was God. He directed all worship to his Father. (Luke 4:8)
Archangel Michael is a separate person. They cannot be one.
I believe they can. Who but an archangel speaks with an archangel's voice? If God used his own voice at Jesus baptism, why use the inferior voice of a lesser being to call his anointed to heaven?
The other illogical understanding (in question) is this: How can (Jesus) archangel be worshiped by his own angel? Contradictory.
Heb.1:5-6
5. For to which of the angels did He ever say,
"Thou art My Son, And again,
6. And when He again brings the first-born into the world, He says,
"And let all the angels of God worship Him."
What contradiction? The pre-human Jesus was no ordinary angel. He was the first and only direct creation of his father. All other things were created through the agency of the son. (Col 1:15, 16; Prov 8:22, 30, 31) That makes this "son of God" superior to all the others. There are many "sons of God" mentioned in the Bible, but this son is "only begotten". He is a unique creation...the beginning of God's creativity. (Rev 3:14)
I believe that you need to do a study on "pro·sky·neʹo" which is the word translated "worship" in the Greek scriptures.
In 1 Cor 15:27 it is clear that all things are subject to Jesus except the Father himself. That would include all the other angels....but nowhere is Jesus "worshipped" in the same way that Almighty God is worshipped. Pro·sky·neʹo can be rendered "obeisance" just as it should be when the magi honored the one born "king of the Jews". They were not worshipping Jesus as a god, but giving him honor as a child of royalty.
Some translation only render pro·sky·neʹo as "worship" but that is misleading. Some correctly render it by such expressions as “bow before” (AT; Yg) and ‘pay homage’ (NE) which is its wider meaning. It doesnt always denote the kind of worship offered to a deity.
"The Greek word pro·sky·neʹo corresponds closely to the Hebrew term hish·ta·chawahʹ in expressing the thought of obeisance and, at times, worship. The term pro·sky·neʹo is used in connection with a slave’s doing obeisance to a king (Mt 18:26) as well as the act Satan stipulated when he offered Jesus all the kingdoms of the world and their glory. (Mt 4:8, 9) Had he done obeisance to the Devil, Jesus would thereby have signified submission to Satan and made himself the Devil’s servant. But Jesus refused, saying: “Go away, Satan! For it is written, ‘It is Jehovah your God you must worship [form of Gr. pro·sky·neʹo or, in the Deuteronomy account that Jesus was quoting, Heb. hish·ta·chawahʹ], and it is to him alone you must render sacred service [form of Gr. la·treuʹo or Heb. ‛a·vadhʹ].’” (Mt 4:10; De 5:9; 6:13)" (Insight Volumes)
In Australia, which followed the British legal system, judges used to be addressed as "Your Worship" denoting that they held a position of respect. The American system called them "Your Honor" demonstrating the same thing.
You assume too much. Do some deeper study and research. Its amazing what you can find. Read the scriptures provided and comment on them.