I have fought with this in my own mind very often. I have a few imperfections that I feel are deal breakers in the end, and I can obsess over them (luckily I think I am going to sort of one of them out later this year, as I actually can do something about it). It does seem like about 85% of the guys that approach me, and show interest, I am just not interested in. Not physically attracted to them. I am honest about it, and let them know, and it can be disheartening that is for sure. The worst is when someone approaches me without knowing what they look like, they seem to have a good personality, then when I see what they look like, it kills everything. That really sucks. Once in a blue moon someone who I do think is attractive will approach me, but either their personality won't work, or they're taken already the vast majority of the time.
Approaching guys does seem to lend to a lot of deaf ears, but now and then I'll catch something, and it can become something more. You just have to approach it like you are getting to know a friend for the first time. If you go into it with that mindset, then you're less likely to screw up.
In the end though, is it really 100% true that you get turned down by ALL guys you're attracted to? Even if just one or two respond, then that is indeed better then nothing.
I just met someone the other day that I find physically attractive, has a fantastic personality for what I need, and I approached him. It's definitely got potential to become something more too. It can happen, just keep looking.