Why are so many against it? SPIRITUAL BLINDNESS!
Many people miss the point of Matthew 28:19 as it mentions the Name of the Father, Son and Holy Ghost being Jesus.
The amount of stress that is put upon the name of God in the Old Testament is put upon the name of Jesus Christ in the New Testament. The trend to exalt God's name and to praise and call upon His name in OT reading is continued in NT writings, but the name mentioned and stressed, exalted and praised, is JESUS' name.
This in itself proves that the name of Jesus is indeed the Name of the God of the Old Testament. Where is there stress of any other name in the New Testament? You cannot find another name stressed so highly besides "Jesus."
But when they believed Philip preaching the things concerning the kingdom of God, and the NAME of Jesus Christ, they were baptized, both men and women.
Be it known unto you all, and to all the people of Israel, that by the NAME of Jesus Christ of Nazareth, whom ye crucified, whom God raised from the dead, [even] by him doth this man stand here before you whole.
But when they had commanded them to go aside out of the council, they conferred among themselves, Saying, What shall we do to these men? for that indeed a notable miracle hath been done by them [is] manifest to all them that dwell in Jerusalem; and we cannot deny [it]. But that it spread no further among the people, let us straitly threaten them, that they speak henceforth to no man in this NAME. And they called them, and commanded them not to speak at all nor teach in the NAME of Jesus.
And whatsoever ye do in word or deed, [do] all in the NAME of the Lord Jesus, giving thanks to God and the Father by him.
Simeon hath declared how God at the first did visit the Gentiles, to take out of them a people for his NAME.
Philippians 2:9 Wherefore God also hath highly exalted him, and given him a name which is above every name:
Paul said that Jesus is the name above every other name, including every other name God formerly revealed of Himself! If Jesus is not God's name, then we have a being who possesses a name greater than God's own name! Jesus must be God's name!
Isaiah prophesied about the truth of all people bowing to Him:
I have sworn by myself, the word is gone out of my mouth [in] righteousness, and shall not return, That unto me every knee shall bow, every tongue shall swear.
And we read in the New Testament a direct fulfillment of that verse, which interprets it as saying that God's Name is Jesus:
That at the name of Jesus every knee should bow, of [things] in heaven, and [things] in earth, and [things] under the earth;
FATHER, SON AND HOLY GHOST
Jesus is the name that encompasses all three roles since it is the one Name given for salvation:
Neither is there salvation in any other: for there is none other NAME under heaven given among men, whereby we MUST be saved.