IIRC from high school psychology, so forgive me if I'm way off base, but I don't think fetishes for sexual characteristics are actually fetishes.

Asking why a fetish isn't common is kinda oxymoronic, in a way, considering all true fetishes are pretty rare. If you just mean 'why aren't they seen as attractive by straight women/other male-attracted groups' then I can assure you they are.

The whole neck, collar bone, shoulder and peck area is like, my favorite part of the male form, and I am not alone by a long shot. Maybe talk to more women about this stuff lol.

Lots of us appreciate several parts of male anatomy in similar ways that straight men do female anatomy.

You haven't lived until you've had your apple sucked!

I don't think it counts as a fetish if it's a common thing to be attracted to

I dated a woman who said Adam's Apples were one of her favorite features on a man. I wouldn't say it was to the point of being a full blown fetish, but definitely something that she paid attention to. If I had to guess, I'd say she's probably not the only one out there that feels that way.

I mean maybe it is if you count chasers?

Mostly it's just that it's not super noticeable on it's own, not even in the indirect way something like the prostate can be