Some sprays are more effective than others obviously.. but I see what you're saying. But that's also why you'd be carrying a gun if it doesn't work.
The pissed off dudes would still be hitting you with their bats. Period. no doubt. I've seen it with my own sprayed eyes lol.
and now, you'd be in the fetal position trying to blindly fire your gun. Good luck there.
Dude - the entire confrontation will be over in 10 seconds. thats it. One of you will be incpacitated in less than 10 seconds.
You use the spray and it all goes sideways. You use the gun, and chances are you win.
SOLUTION - Fire 2 warning shots into the floor and yell "Say hello to my little friend - Bring it on cockuckers, you're gonna need a fcking army you wanna take me".
90% of bad guys will flee immediately.
Then, you lie prone on the floor while the wifey calls 911 from the bathroom, and you triple tap center mass any shape that enters that hallway. They've been warned.