My friend in Wyoming thins everything
--but not willy-nilly. He's a very learned knife collector and user. He is a careful 'slicer,' and he would never thin a blade without study and a consultation.
As you know, a gentleman by the name of Dwade Hawley, the best sharpener/polisher I know of--at least on our hemisphere--gives my friend parameters and suggestions on alloys and use. They take good quality nakiris past 8 degrees, but leave Striders at 15 to 18 degrees. They're not metal butchers, they just like thinned blades--if appropriate.
That is not my situation. Unless the client specifies, I pretty much refine and repair the existing edge and factory degree setting. Yes, in making a bevel uniform from front to back and then left to right, this refinement by use and definition thins part of the blade.
For my use on personal Japanese knives (the ones without that thick bolster) I thin the heel, and on most good quality Japanese laminates, at least the 'gooder' type, this thinning is minor. It's more making the entire edge more uniform.
Yes, most Ran Damascus knives arrive a bit thicker and some near +/-20 degrees. Even if I re-profile just a smidgeon, the edges get incredibly sharp, if a good buff finishes the procedure.
I have what is known in the trade as a "soft" or a "slow hand." I always did, but I'm even more careful after studying the strokes I've seen watching real Japanese sword polishers on youtube.
My overall opinion is that if you need to thin off that much steel you either have the wrong knife or an ego problem.
Pictured below is a nakiri I refined, thinned, polished and 'repaired.' That front portion was amazingly poorly formed from the factory. I made it perfectly round so it would 'roll' smoothly if the chef made a backstoke through a tomato by keeping the edge in contact with the cutting board.