First 'it makes good sense' to you and one or two others. Everyone that builds scifi on this forums that has weighed into this topic has told you it does not make good sense at all.
Another good point has been brought up as well. As I said fantasy is sword and sorcery and mythology mostly has to do with grecko roman mythos and at times norse.
Now ALL of that 100% absolutely, positively ALL of it is pre-history to medieval, meaning there is nothing more advanced then a axle and a wheel which means that 99.9% of it ALREADY fits into the category of 'Figures'
If you made a category called 'Fantasy' what you would effectively do is split the 'Figure' category into ' 1600-present and prehistory to Renaissance. While there are a lot of historically accurate medieval and crusades figures the majority of figures done by people, especially on THIS forum, are WWII - Modern 1/72nd to 1/35th scale figures.
Let me do some searching for you, in the genre of fantasy
http://www.scalehobbyist.com/catagories/Scale_Figures/browse.php?s=0&t=5&u=4&pg=1&ppp=24&sb=stocknumber&so=a
http://www.monstersinmotion.com/cart/index.php?main_page=index&cPath=271_279&sort=20a&page=1
SOME of the kits from the following
http://www.moebiusmodels.com/
http://www.hobbylinc.com/cgi-bin/s8.cgi?cat_s=S&mfg_s=pll&p=2 (because polar light's site isnt working)
It took me a long time to find some fantasy model kits that were not just half naked women with pointy ears.
now, lets try Scifi
as quickly as I can here are three
http://www.gundamstoreandmore.com/gundam.html
http://www.starshipmodeler.biz/shop/
http://www.hlj.com/top/Sci
Last thing Ill put here now is just a restatement of what I said earlier. Fantasy kits are 99.999% Figures thats all, they go in the figure category and they always have. Its called Scifi for a reason, contests call it scifi, stores call it scifi. If you want fantasy stuff you either look in Figures or in Scifi because there are few of them and when you find them they are just that, figures.
It would be like taking another overarching subject... this is even hard to do, lets try automobiles, and saying... nah, lets take a small little niche model type, lets do drag racers, and lets call the category drag racers.