Why do so many male models look like they have no sex appeal?

Because they are supposed to look like mannequins so clothes look good. Clothes are the important thing. For models with sex appeal you have to turn your attention towards bodybuilding categories where men's bodies are the object of admiration.

Most female model lack sex appeal too. It's their job to look pretty but bland.

R1 Eh I also find the bodybuilder types to be kinda meh, too plain faced and/or the bodies are too disproportionate looking. I've been turned on the most by gay swimwear/underwear models where they seem the most harmonious.

What kind of models are you referring to, OP? There are different categories from high fashion to commercial to underwear and swimwear. I'm assuming you mean high fashion, the ones you see in ad campaigns for Prada, Gucci, and YSL.

Alcohol & Drugs

What R1 said. By "models" I'm assuming you mean high fashion models, they're bland and sexless by design.

Some current high fashion models.

Because you want models to be bland, that way you can fix them up or down.

The ideal male model is 40" chest / 30" waist. You can then pad them up to achieve the fit you want. Same for looks. The blander the better.

When you show clothes you want people to look at the clothes not the model. If the model was too good looking the person who was potentially going to buy would say "So what? You put a garbage on him and it'd look nice." You wouldn't want that.

You want the person to think the clothes are what will make them look nice.

Aussie and Dutch model. The blond parties with Michelle Rodriguez.

R7 That's another thing that surprises me, the endless tobacco/nicotine promotion.

Bland?

R11 Those guys are not high fashion models tho.

You know a high fashion model I really find revolting to look at? Sean O'Pry. Looks like an emanciated reptile.