Why not 316L?

Regardless of what razor I use (303 Steel, 304 Steel, 316 Steel, Aluminum, Titanium or Zamak), I always remove the blade, clean and dry the razor completely. With my process, all of my razors look brand new, therefore the material of the razors...from a durability standpoint, is a non-issue. How a razor shaves, and the enjoyment it provides is all that matters.
I observed my dad in the 50's and 60's...shave, shake the moisture off the razor and place it on the sink or the medicine cabinet until the next day. I suspect that many shavers today will follow that same procedure...which contributes to quicker levels of razor corrosion in certain razor materials.
How a razor is treated, is a huge contributor to people having corrosion issues with their razors (assuming they had no defects when purchased).

If you plan to place your razor in a pirate's chest at the water's edge and want it to remain pristine for a few decades, then 316L is your steel of choice. If you want your razor to resist corrosion when exposed to a ruptured chlorine tank car, the 316L will last longer.

There is no added functional benefit of 316L in a razor unless you plan to spend much time shaving while scuba diving.

Isn’t this why we’re all here though? DFS is Deepwater Fishing Shave right??

Traditional wet shaving. Where anything worth doing is worth overdoing   Dare I say it? It’s just a razor.

I know some people do remove the blade from the razor between shaves. Some even reorient the blade in the razor when reinstalling it  following the numbers printed on the blade.  However, I have seen a number of blades where the manufacturer warns not to wipe the blade and to leave the blade in the razor to prevent damage to the coating. Of course, it is your razor, your blade, and your face, so you can do whatever you wish. 

While performing razor blade evaluations, I have used a blade for one shave and then left the blade in the razor for a few strokes during the subsequent shave for comparison purposes.

Normally, I shave using four different razors, each with their own blade. I use a different razor/blade combination for each of my four shave passes. The blade used for the WTG passes gets the most wear and might be replaced after a half dozen shaves. The blade used for my 4th clean-up pass might last 16-20 shaves since it is only picking up stray stubble. In that situation, the blades remain in the razors until they are no longer sharp enough or smooth enough to do their job. There is no way I am removing four blades from the razors after my shave. 

When using a straight razor, especially one made of carbon steel, I carefully dry the blade, apply a mixture of 91% rubbing alcohol and mineral oil and store the razor away until I use it again. The fine edge of a carbon steel blade does corrode readily, so drying and oiling it helps prolong the life.

I have heard the same thing from some manufacturers, same issue with titanium that it wears out the tools much more quickly and requires more attention and maintenance.