So far, for me and my lifters, a dynamic start is a personal preference AND I only let people experiment with it once they are solid with the basics.
In reality, this means that I only have a few lifters who do it at all. I've never actually suggested it to anyone. A few of my more advanced lifters have adopted a dynamic start as part of their personal routine. I just switched my snatch to a dynamic start because I completely changed my start position, but working with a dynamic start on the clean feels screwed up.
In my experience, one of the most common problems that beginners have is letting the bar get too far away from them. I want people to get very good at pulling super slow off the floor, and adding a dynamic start just incorporates one more element that they can screw up - and it probably adds ZERO kilos or confidence to the lifts of a beginner.