Two words...high maintenance! I think when you look too made up they think that and run in the other direction. I don't think all men are that way though. There are some who like it.
My problem was a little different...when I was married the first time guys always flirted with me. Funny I thought because I was wearing a wedding ring. But...when I was widowed and wanting the attenion, lol ,nothing! The ring was gone and so was the flirting. My kids always say I flirt but I don't...I am friendly...when people talk to me I talk to them, men or women. Just happens to be more men than women, lol.
I've gotten a few men hitting on me when I'm looking a mess, though most of them are the kinds of guys I wouldn't be caught dead dating to begin with. Honestly, the kinds of guys I would date usually only hit on me at the typical "meeting people" places: clubs and bars. Most of the very hot guys in the general populus happen to be taken... or man whores.
I think women dress up and do the makeup thing for other woman - not for men. I'm talking about mature men now - not high school or even early college types - but men don't seem to care about looks as much as I thought they did. I have MAJOR self esteem issues and have since I was a teenager and tiny. Being overweight has only made it worse but I have noticed that when I'm feeling good I get hit on. I think men look for someone aproachable who has a good attitude and a good sense of self - confidence. I see tons of women who are beautifully made up and dressed and they look nasty and unapproachable as ****. Maybe you're feeling way more comfortable when you are just being "you". Men feel that and are drawn to it.