When and why did Protestantism begin moving away from liturgy? I have been to some Protestant churches that have a liturgy on Sunday mornings (Lutherans, Presbyterians, etc) but most of the churches I've attended do not (Baptist, Assembly of God, etc). By liturgy, I mean specific readings, usually chosen according to a church calendar, from a pool of shared, historical literature compiled by the church over time.

When and why did Protestants who follow the 'sing a few songs and then listen to the Pastor give a sermon' tradition abandon the liturgy in favor of worship music followed by a sermon? I am not asking about praying the hours throughout the day but rather about the church service.
The simplifying or outright dismantling of liturgies has been in train since the beginning of the Reformation, particularly as it started to unfold in Switzerland under Huldrych Zwingli. From the linked Wikipedia article:


  Shortly before Easter (1525), Zwingli and his closest associates requested the council to cancel the mass and to introduce the new public order of worship...The sermon was the focal point of the service and there was no organ music or singing.


They still did describe the order of service as a liturgy, but there was a radically new conception of what that meant.

In many ways, Zwingli was more "Protestant" than Luther - his rejection of the concept of the real presence in the Eucharist and limiting communion services to four times a year was a major step towards a "de-liturgized" service.