It's more like the MM's and big traders that got away with the practice of shorting without any penalty for years are the ones retiring and as you call it "getting out of the kitchen"
The playing field is changing and laws promoting ethical trading are being put into place. The brokers free ride is going to come to an end soon.
------------------------------------------------------------ "If they can't stand the heat, get out of the fire, there will always be others to replace them."
Market Data 
Markets 
AI
