I don't tolerate poorly-trained hospitality personnel. I worked in the restaurant industry, both in a brewery and waiting tables/tending bar.
Tell you what the difference is: I take pride in my work.
When I brewed full-time, the staff knew what the beer tasted like, how to describe it, a basic roster of ingredients. All of them knew the process (and most spent at least one day a month in the brewery) and could describe it. Flagships and seasonals; didn't matter.
When I worked the front of the house, I knew the specials, I knew the beers on tap, the drinks specials, you name it. I always upsold dessert.

And I'm not the smartest guy; my memory stinks. But I worked at it,
because it was my job. That's why I'm so impatient with poor service.
I cannot abide arguing with people about what I ordered. Happened to me in a restaurant in New Hampshire a coupla months ago. They've got SA Winter Lager. Great! I'll have one. They bring me Boston Lager. I start out nice, 'cos I know mistakes happen.
Me: I'm sorry, Kevin; this isn't the right beer. There must have been some mistake.
Waiter: Oh, gosh - let me get you another. [pause] Here you are.
Me: Sorry, Kevin; still the wrong beer.
Waiter: But the bartender...oh, damn. I'll be right back.
Me: [waits]
Manager: [walks over with Kevin] Here you are, sir.
Me: Sorry, lady. Still off.
Manager: [increasingly snooty] I've checked the taps myself.
Me: Check the kegs. It happens.
Manager: [irritated as hell, presumably because this mere
customer is infringing on her smoke break] Sir, I...
Me: Missy, look. I've spent more time in a brewery than you have in a bra, okay? I know beer when I see, smell and taste it. I've had more Boston Lager than you've had iced tea. The beer coming out of that tap is Boston Freakin' Lager. Now check the thrice-damned keg, and be quick about it!
Manager: I'll do that. [stomps off in huff]
Waiter [horrified look on his face]: Man, I am so sorry.
Me: You're sorry?! All I wanted was a frelling beer!
Wife: [giggle giggle, seen-it-all-before giggle]
[Manager returns] Sorry, sir; it appears the kegs were mixed up.
Me: There ya go. The moral of the story is that the customer is always right. Now make sure you clear the lines before you bring me a pint of what I ordered, K?
Got three pints for free, too, plus dessert.
I never take it out on the server, unless the server richly deserves it. I take it out on the management. After all, management has the responsibility of training their staff and running a friggin' restaurant. If they can't or won't do that, they deserve an ass-chewin', and if her boss won't do it,
I sure as shootin' will. In front of the server, always.
Including the server, if I'm really peeved. Usually, if the food order hasn't come out, that's when I simply get up and leave.
Know what I got? It ain't nerve. It ain't being a 'beer penis'. It's
standards. And I never let 'em slip.
Bob