St. Paul said pray without ceasing. There are many forms of prayer. Discursive is one, but not the only one.
Some are called to other practice of prayer. It is always to be under proper guidance by a competent spiritual director.
Most or all Protestant churches shut down or rejected monastic and other orders and so lost this competency. Since then, in most cases, what replaced it was incompetent practitioners as you mention, or rejection of any other form of prayer than discursive.
Both are a loss.
By the way, it was largely due to Merton that I converted from buddhism to Christianity. IMHO, there are many who misunderstand his gift to our faith.
Well...since Protestants form their doctrine on prayer from the Bible, and not church tradition, we disagree because the Bible holds to one form.
Some are called to other practice of prayer. It is always to be under proper guidance by a competent spiritual director.
Protestants don't have, or need, "spiritual directors".
Protestants don't pray by emptying their minds through breathing, body posture and relaxation techniques. We don't come to know God through "silence". Our revelation of God comes through the completed Scriptures.