I don't see onlylegging.com in the results as you are pointing out but it's not necessarily a bad thing. Think of it this way: If you want to buy a car, do you search for "car" or do you search for the specific car you are looking for?
first off, i'm sure you know that the number of people who use bing is nothing compared to the number of google users. i personally use bing occasionally, but just had to throw that out there.
secondly, it is amazing how onlyleggings.com is coming up FIRST PAGE ON GOOGLE on so many various leggings related online shopping type of searches!
thirdly, i agree, the search of the keyword "leggings" is a very desireable google search for the company to want to have a nice ranking on. but it is more of a general word, used on lots and lots of different websites, and there are so many websites out there around the world that mention "leggings" and have been around a lot longer than onlyleggings.com. a search for "leggings" brings up many pages unrelated to shopping for leggings online, which is why online shoppers often add keywords to cut out unrelated results, and it's easier to go right to the style of leggings you're looking for if you add a descriptor. in spite of this, last week onlyleggings.com came up on page 8 on a google search for "leggings". this week it's coming up on page 7. now that movement occured in only 1 week of progress. let's see how long it takes onlyleggings.com to get to 6, 5, 4, 3, 2, etc on this particular search ...
EDIT: I JUST SEARCHED GOOGLE AGAIN AND ONLYLEGGINGS.COM IS NOW COMING UP PAGE 6. LOL, JUST MOVED UP ANOTHER PAGE ON THIS PARTICULAR SEARCH IN THE LAST COUPLE OF HOURS.
and fourthly, at this rate, with so many different leggings related first page google searches now, and steadily increasing alexa rankings, IMO it's only a matter of time until onlyleggings.com becomes the absolute KING ONLINE LEGGINGS SUPERSTORE.