I think it's many factors.
The style of overalls,how they guy is wearing them and what he has on under them defines if he looks "Hot" in them,or just some old lady's Grandpa.
Twinks with no muscle definition who look like 14 year old boys in overalls=Not "Hot".
Young men with some Muscle in overalls =Hot!
Older men with furry torso's in overalls =Hot!
Women in overalls=NOT Hot!(very unfeminine and unflattering!)
Chubs in Overalls Hot or Not depending on his Girth.
Do I remember the 1980's gay scene explosion of overalls...Yep! Muscular Hunks on the dance floor with the side fasteners undone to their buttocks and one over the shoulder strap left hanging=HOT!

me I like wearing biboveralls because they are comfortable and
I like the farm boy/hillbilly look that biboveralls have.
when someone calls me a farmer or a country hick I take that as a compliment.
I also like seeing guys in biboveralls for the same reasons
I like the rural look that biboveralls have

It's fuckin sexy! Just the fact that a man is wearing something made for serious work and sweat is hot! I love workin in them they leave plenty of ventilation for your back but protect your legs and stomach when carrying heavy lumber brick or what have you. I also love the way they frame a man and show off, somewhat discretly the nibbly parts, pecs, shoulder blades and underarms---Yumm!

It's the look for me. I find them just as hot as sweats or a kilt on a man. And for so many reasons. The freedom to wear nothing underneath, accessibility,... the fit, the feel,...

It is still a HOT look as many of the photos show!

I absolutely LOVE how overalls look. Any man who wears them automatically gets sexier, imo.

For me if they are well worn and dirty from working on a car or tractor then the smell gets me hard. Comes from when I was teenager in Birmingham England and all the good looking men wore them.