I think a lot of fanficcers feel that way.
Sometimes it is so obvious you can practically see that pool of drool on the writer´s keyboard. *g*
For me, this kind of fic that revels in the physical beauty of one or both parts of a pairing is almost a genre by itself. I call it drool-fic.
You know, these stories that make you smile indulgently and think "Have it bad, eh?" :-)

By sheer coincidence I came upon such a story shortly after I read your entry, a Highlander rec on crack_van, an AU featuring Duncan McLeod as a waterhorse, a shapeshifter who takes the form of a magnificent stallion (oh, subtle!) one moment and turns into a gorgeous human male the next - a gloriously naked male, I should add.
Should this in any way remind you of Pratchett´s Greebo, don´t worry: no similarity whatsoever!
The moment when Methos turns and sees the creature in its human form for the first time is drool-fic par excellence!
Not that I dislike it, I quite enjoy it once in a while, but as I said: it makes me smile a bit. :-)
It´s the female equivalent to a bunch of males admiring Pamela Anderson´s boobs. Only women do it so much more elegantly and inventively than the average male.
That´s another reason why I love fanfic!