> I somewhat expected my post would generate this type of attack

It may not have been your intention but your post had a combination of a somewhat smug, lecturing tone and patting oneself on the back which is a bit off-putting. And implicitly made a lot of assumptions about other parents' intentions/lived experience raising their children based on a single factor that's pretty insignificant like # of sq ft of child's belongings kept in the family home.

Also, for all you knew at the time you replied, OP could've still had stuff in their parents' attic because they joined the Marines at 18 and was even more independent than your own kids. There was a lot of projection onto a trivial story.

Plus "must be a generational issue" just sounds like more of the same "my generation was responsible/good/normal unlike kids these days" meme that gets repeated by every generation as they age and is tiresome to hear as an explanation for everything.