While there are certainly no lack of arguments over whether or not the capacity of a revolver is sufficient, I think perhaps you don't see capacity, for lack of a better term, obsessed over in revolvers like you do semi-autos because of the other fundamental differences between the two platforms.
A revolver has many attributes that are quite different from most semi-automatics besides just capacity. Those of us who gravitate towards revolvers (myself included) tend to place more weight on attributes like the power of the cartridge, reliability (which is a whole different rabbit hole in and of itself), simplicity, etc. above capacity because, frankly, even the lowest capacity semi-automatics can equal or exceed that of most revolvers. Also, revolver guys don't really get too hung up on the capacity of one revolver over the next because the difference is usually one or two rounds.
By comparison, often the biggest difference between two semi-automatic pistols is their capacity. For example, a S&W Model 39 and Beretta 92FS are both of similar size, action, construction and have very similar manuals of arms, however the S&W holds 8 rounds in its magazine while the Beretta holds 15. Also, the difference in capacity from one semi-auto to another of similar size is often much greater than the difference in capacity between two similarly sized revolvers. For example, a Colt King Cobra or Kimber K6S both hold 6 rounds as opposed to the 5 of a Ruger SP101 or S&W Model 60 . However, a Sig P365 can, depending on the magazine, hold 10-12 rounds as opposed to the 7-8 of the original S&W M&P Shield 9mm.
Basically, semi-auto guys tend to argue more about the capacity of this gun over that one because, frankly, semi-auto guys are more likely to place capacity further up the list in their hierarchy of important features on a defensive handgun than revolver guys are.
A revolver has many attributes that are quite different from most semi-automatics besides just capacity. Those of us who gravitate towards revolvers (myself included) tend to place more weight on attributes like the power of the cartridge, reliability (which is a whole different rabbit hole in and of itself), simplicity, etc. above capacity because, frankly, even the lowest capacity semi-automatics can equal or exceed that of most revolvers. Also, revolver guys don't really get too hung up on the capacity of one revolver over the next because the difference is usually one or two rounds.
By comparison, often the biggest difference between two semi-automatic pistols is their capacity. For example, a S&W Model 39 and Beretta 92FS are both of similar size, action, construction and have very similar manuals of arms, however the S&W holds 8 rounds in its magazine while the Beretta holds 15. Also, the difference in capacity from one semi-auto to another of similar size is often much greater than the difference in capacity between two similarly sized revolvers. For example, a Colt King Cobra or Kimber K6S both hold 6 rounds as opposed to the 5 of a Ruger SP101 or S&W Model 60 . However, a Sig P365 can, depending on the magazine, hold 10-12 rounds as opposed to the 7-8 of the original S&W M&P Shield 9mm.
Basically, semi-auto guys tend to argue more about the capacity of this gun over that one because, frankly, semi-auto guys are more likely to place capacity further up the list in their hierarchy of important features on a defensive handgun than revolver guys are.