But what exactly is the criteria for "Young Forty" fashion?

These days, even Nike is getting mocked as something only "Young Forties" wear lol
If it's not summer clothing, I almost always buy my clothes from Polo.
Since the weather has gotten chilly lately, I wore some out, and they told me it looks like "Young Forty" fashion ㅋㅋㅋㅋㅋ
I was like, "Huh?" because I thought Polo was just decent casual wear, not something to be ridiculed for ㅋㅋㅋㅋㅋ
But they said it's what Young Forties wear ㅋㅋㅋ
Well, I don't really care what they think, but those Young Forties are getting old lolol ㅋㅋㅋㅋ
But seriously, what is the criteria for labeling a brand like that?