I didn't have an opinion on tins until I made the first conscious notice of pies being thrown without tins. Now when I go back and look at all the videos that use tins I can't help but feel that something's off.
You have to do that jiggle to make sure the crust doesn't stay in. You have to lightly peel it away to make sure the pie stays on. I think everybody's looking for the slow "slide off" look like in our smiley

but that almost never happens because real life physics gets in the way. So they have to remove the tin from the face when it would've been a better idea to just throw a non-tin pie in one motion. It makes for a "cleaner" production.
I also think tins hinder new pie throwers. They have to be warned not to throw it so hard, they're probably mindful of getting the crust out, they want to smush but not cut. So sometimes they end up holding the pie awkwardly (by the edge) because they want to get everything perfect. If you hand a new pie-er a pie without a tin you don't have to give any further instruction than "go crazy."