In short, what patriarch, what prophet, what Levite, or priest, or ruler, or at a later period what apostle, or preacher of the gospel, or bishop, do you ever find the wearer of a crown? I think not even the temple of God itself was crowned; as neither was the ark of the testament, nor the tabernacle of witness, nor the altar, nor the candlestick crowned though certainly, both on that first solemnity of the dedication, and in that second rejoicing for the restoration, crowning would have been most suitable if it were worthy of God.
But if these things were figures of us (for we are temples of God, and altars, and lights, and sacred vessels), this too they in figure set forth, that the people of God ought not to be crowned. The reality must always correspond with the image. If, perhaps, you object that Christ Himself was crowned, to that you will get the brief reply: Be you too crowned, as He was; you have full permission. Yet even that crown of insolent ungodliness was not of any decree of the Jewish people.
It was a device of the Roman soldiers, taken from the practice of the world—a practice which the people of God never allowed either on the occasion of public rejoicing or to gratify innate luxury: so they returned from the Babylonish captivity with timbrels, and flutes, and psalteries, more suitably than with crowns; and after eating and drinking, uncrowned, they rose up to play. Neither would the account of the rejoicing nor the exposure of the luxury have been silent touching the honour or dishonour of the crown. Thus too Isaiah, as he says, “With timbrels, and psalteries, and flutes they drink wine,” would have added “with crowns,” if this practice had ever had place in the things of God.
Source: De Corona (The Chaplet) (New Advent)