While jumping in without fins on makes little sense, when I originally did my cert through nasds in the 70's, they taught bailout. which is basically holding all your gear and jumping off the boat. mask, fins and weightbelt in one hand and tank/reg in the other. As of today I have yet had the need to "bailout' from a boat.
We had the same very old school but very useless drill too.
It was right up there with piling the whole classes gear in a big mound on the bottom of the pool and having everyone come up after one beathe held dive properly attired in your own gear. Compared to the bail out drill, at least it did require some water skills, some cooperation, team building, prioritizing and problem solving.
----
Personally, I think the giant stride is over rated. It is designed to limit the depth you reach on the initial entry and it is designed to get you back to the surface. That makes snese if you are jumping into shallow water or for some reason need to return to or regroup on the surface. I'll use it if someone has to hand me my camera - otherwise, probably not.
Plunging in feet together is not always bad. For example, jumping off the dive boat in clear, deep water with a strong current is a place where going in negative and getting down to the current/descent line quickly and in good order where you can link up with the buddy, do a bubble check and get on with the dive is an advantage. Bobbing around on the surface doing the padi approved Ok'ing to everyone while you drift off into the sunset is really not an advantage in that situation.
I am dogmatically opposed to anything that smells of dogma or indoctrination. I believe that what ever you do in diving needs to have a reason and a purpose that also adds something to the specific dive you are doing. If you do not fully understand it or know why you do it, you are pretty much just along for the ride and are an accident or emergency waiting to happen. "Stop. Breathe. Think." is about as dogmatic as I get, everything else is relative and negotiable.