Personally, I don't think it makes all that much difference, but of course there are times it "might" spook the fish. However, how would you know if it was the "ping" doing the spooking or the presence of the boat, its shadow, trolling motor noise and/or prop wash, etc. ??

I say that I don't think it makes much difference, because I've caught Crappie (& Bass) in very shallow water (<5ft deep) ... with a depth finder turned on the whole time, and even prop washed the spot with the trolling motor in order to not run the boat into the bank, tree, or any other obstacle in the area. In these instances, my boat was the only "intruder" in that otherwise calm environment.
And that's all from the use of 2d depth finders, whose ping is directed straight down in a cone shape. So I have to ask ... why isn't DI, SI, 360, and Livescope/Livesight units "spooking" fish away from the boat, when their ping is directed in a much wider area ??

That's not to mention that I've seen pontoon boats (w/o a trolling motor) run right up on the bank or crash right into a stand of trees ... tie off and begin fishing, and catching fish. If that noise/disturbance doesn't always "spook" the fish and send them running to the far ends of the lake, then I don't see how the ping of a depth finder would.