This series of quotes from Baptists and non-Baptists of the past and present reveals that Baptists did not originate with the Protestant Reformation. As a matter of fact, many of the Reformers severely persecuted Baptists. Therefore, a true Baptist should not celebrate Reformation Day as it does not apply to us and celebrates those who actively sought to eradicate us. For additional information about the persecution of Baptists, a good source is the Martyrs Mirror.
Here are the Baptist Origin quotes for today.
"Were it not that the baptists have been grievously tormented and cut off with the knife during the past twelve hundred years, they would swarm in greater number than all the Reformers." Cardinal Hosius (Letters, Apud Opera, Pages 112-113)
"We shall afterwards show the rise of the Anabaptists took place prior to the Reformation of the Church of England, and there are also reasons for believing that on the Continent of Europe small hidden Christian societies, who have held many of the opinions of the Anabaptists, have existed from the times of the apostles. In the sense of the direct transmission of Divine Truth, and the true nature of spiritual religion, it seems probable that these churches have a lineage or succession more ancient than that of the Roman Church." Robert Barclay (The Inner Life of the Societies of the Commonwealth, 11, 12, London, 1876)."
"The true origin of that sect which acquired the denomination of Anabaptists by their administering anew the rite of baptism to those who came over to their communion, and derived that of Mennonites from the famous man to whom they owe the greatest part of their present felicity, is hidden in the depths of antiquity, and is, of consequence, extremely difficult to be ascertained."
"Before the rise of Luther and Calvin, there lay concealed, in almost all the countries of Europe, particularly in Bohemia, Maravia, Switzerland, and Germany, many persons, who adhered tenaciously to the following doctrine, which the Waldenses, Wickliffites, and Hussites, had maintained, some in a more disguised and others in a more open and public manner; viz. 'That the kingdom of Christ, or the visible church which He established upon earth, was an assembly of true and real saints, and ought therefore to be inaccessible to the wicked and unrighteous, and also exempt from all those institutions which human prudence suggests, to oppose the progress of iniquity, or to correct and reform transgressors.'" Johann Lorenz Mosheim (Mosheim's history, pg. 490)
"We have now seen that the Baptists, who were formerly called Anabaptists, and in later times, Mennonites, were the original Waldenses, and who, long in the history of the church, received the honor of that origin. On this account the Baptists may be considered as the only Christian community which has stood since the apostles, and, as a Christian society, has preserved pure the doctrine of the gospel through all ages. The perfectly correct, external and internal economy of the Baptist denomination tends to confirm the truth disputed by the Romish Church, that the Reformation, brought about in the sixteenth century, was in the highest degree necessary; and, at the same time, goes to refute the erroneous notion of the Catholics, that their communion is the most ancient." Rev. J.J. Dermot, Chaplain to the King (My Church by J.B. Moody, pp. 311)