It's used as a stupid, empty shutdown of discussion,

I mean, I don't see how it shuts down the discussion. You are free to respond that despite the date it's okay to cling to past traditions that the current zeitgeist views as a mistake. Ironically, calling the phrase 'vapid, stupid, empty' etc definitely seems like an attempt to shut down discussions.

It's used as a stupid, empty shutdown of discussion, with ignorance of how changes get accomplished.

You are either misunderstanding what bringing up the year means or I think you misunderstand how things get accomplished. No one thinks the simple passage of time is all that's required for progress. Saying that is the point is a strawman. The point of the phrase is that people have recognized the very real trend of society improving (however slowly) over time.

Of course progress isn't and inexorable forward march, everyone knows this. Obviously if some people didn't feel that society was regressing, they wouldn't bother bringing up the current year.

I like how you made and exception for the one thing you personally agree with, but everything else ifs vapid, stupid, empty bs. That kind of thing is why people are associating it with alt-right, because those are usually the kind of people that argue that regression is progress. "So what if it's 2019, does that make it wrong to beat my wife, oppress minorities etc?"