The question started by a joke about t*he hell for tall guys to find fitting T-shirts, like size L shows your navel every time you raise the hands, and size XL expect you to have some beer belly so you end-up floating on the clothes. Somehow at that poing better get a navel piercing and wear a crop tops like ladies do. *
So why did crop-top never became popular for men ? There was a few designer trying to sell some. But it’s not something you’ll see in the wild.
I can hear the whole But we’ll see overweight middle-aged men hairy bellies but it’s not like middle-aged overweight women don’t exist.
Definitely not a “never” .
In fact I hail from a European culture where the traditional grab has men proudly showing ( a lot of) midriff. (Detva region in Slovakia)
https://imgur.com/a/oSPdcxI
As others mentioned western/American fashion had sporty types wear crop tops in the 70s-90s
Here is Will Smith wearing a crop top in Fresh Prince From Bel Aire https://imgur.com/a/0OAZRpi
And yes - if you hang in certain circles men wearing crop tops is still perfectly acceptable. But currently it’s usually associated with femme-presenting queer men of other wise gender noncomforming people.
Straight men seem to have have shunned the look (as they tend to) when it became associated with queerness.
And. Of course all of this is US centric. Plenty other cultures and fashions out there.
Ps: Yahoo seems to think it’s time to bring the crop top back. So hey - you can be a pioneer: https://www.yahoo.com/lifestyle/return-men-crop-tops-why-210039991.html
Mario Lopez used to wear them in the saved by the bell years too. Plus all the “hair bands” that wore them. In addition to the weight lifters and other “sports types”. They really were pretty popular for a bit there.