What are your establishment's risks (in dollars) for criminal (assault and battery) or negligent (liquor liability - underage and/or over service) acts by your employees, or acts occurring on your property? Some cities such as New York now have laws, ordinances or “guidelines” as to what minimum security measures or equipment bars and nightclubs should or must provide For the vast majority of cities and counties that do not mandate such requirements, the ” based on the nature and location of each individual establishment, and, the reasonably foreseeable risks each establishment faces.
Promotions of "two-for-one" drinks, $ .75 "jello shots", or large over-sized drinks, or promoting a three or four-hour long "happy hour", also set a tone and attract specific types of patrons.
That "tone" will also often determine what type problems are likely to arise, and what type and level of security should be provided.
Plus, it makes it more convenient for the hero should he ever need to hide amongst their ranks.
If even hurting them seems a bit extreme, you'll get Mecha-Mooks instead who are beaten till they show broken gears and sparks.
This may be why heroes never have trouble hitting the Faceless Goons, yet the Faceless Goons can't hit the hero not wearing a mask. It's not completely unknown for the good guys' Red Shirt Army to get this treatment, but nowhere near as common.