OK, here's my take on it.
WARNING: Generalizations Ahead!
Men, by and large, are visually attracted. As many have pointed out, straight men get obsessed with feminine beauty as much as gay men get obsessed with masculine beauty.
However, where we differ is that we, too, are men... and so we "know" (intuit) that our looks are going to attract more men than any of our other less visible qualities. And so we become obsessed by our own looks the same way and for the same reason that women do: because we're trying to attract men, and men are (by and large) visually attracted.
Straight men don't obsess as much about their appearance because the people they are trying to attract, women, are attracted to entirely different things than they are. And though women like a good-looking guy the same as we do, the straight guy isn't as conscious of his looks because his looks aren't what he's interested in... he's interested in her looks. While with us, our looks are as important as his looks because it's the same thing. If you see what I mean.
On top of this, men have a greater tendency to quantify things... it's what makes us better at math and linear reasoning. And so a man is much more likely to jot down measurements and quantifiable specifics when framing their own desires for print... straight and gay both. We want dicks a certain size, bodies a certain weight, hair a certain color, etc. And like with looks-obsession, since we're both of us men, you can square the intensity of the situation.
I think one of the other reasons that gay men tend to become obsessed with looks is because we don't have non-good-looking role models available to us: I mean, your grandma and grandpa, your mom and dad are what paired-up people are supposed to look like, what the straight kids know they're going to grow up to look like; but there's very few of us have a dad and dad or grandpa and grandpa for us to look at and aspire to.
There are other reasons I think this occurs, but they're not important... what is important is that we come to understand that looks aren't everything. They're nice and all, I mean I'm not going to start buying magazines with ugly guys in them... but when you're looking for a real live partner in real life, his looks are not it, and neither are yours.
WARNING: Generalizations Ahead!
Men, by and large, are visually attracted. As many have pointed out, straight men get obsessed with feminine beauty as much as gay men get obsessed with masculine beauty.
However, where we differ is that we, too, are men... and so we "know" (intuit) that our looks are going to attract more men than any of our other less visible qualities. And so we become obsessed by our own looks the same way and for the same reason that women do: because we're trying to attract men, and men are (by and large) visually attracted.
Straight men don't obsess as much about their appearance because the people they are trying to attract, women, are attracted to entirely different things than they are. And though women like a good-looking guy the same as we do, the straight guy isn't as conscious of his looks because his looks aren't what he's interested in... he's interested in her looks. While with us, our looks are as important as his looks because it's the same thing. If you see what I mean.
On top of this, men have a greater tendency to quantify things... it's what makes us better at math and linear reasoning. And so a man is much more likely to jot down measurements and quantifiable specifics when framing their own desires for print... straight and gay both. We want dicks a certain size, bodies a certain weight, hair a certain color, etc. And like with looks-obsession, since we're both of us men, you can square the intensity of the situation.
I think one of the other reasons that gay men tend to become obsessed with looks is because we don't have non-good-looking role models available to us: I mean, your grandma and grandpa, your mom and dad are what paired-up people are supposed to look like, what the straight kids know they're going to grow up to look like; but there's very few of us have a dad and dad or grandpa and grandpa for us to look at and aspire to.
There are other reasons I think this occurs, but they're not important... what is important is that we come to understand that looks aren't everything. They're nice and all, I mean I'm not going to start buying magazines with ugly guys in them... but when you're looking for a real live partner in real life, his looks are not it, and neither are yours.

