Paint Can Opener.... Ever notice they still make paint can openers with one end a bottle cap popper and nobody makes soft drinks in pop top bottles.
Only conclusion I can draw is that you are expected to enjoy a good malted beverage after you finish the job at hand. Not the big market Lagers but those micro-brews and imported swill (as they are the only ones w/o screw off caps). A special reward for a job well done.
Why else would they do it? Tradition? A way to hang it up? (a simple hole would provide hanging power) But after enjoying a couple of reward beverages, too many, there may need to be a larger opening to be able to hit the hanger when returning the opener to a place of honor in the shop. So, I conclude that not only is it expected that you open well brewed beverages after application of finishes and painting. You are expected to enjoy several.
I'm sorry, but we must comply.... It is the rules set forth by the manufacturers.