I do not do fondant cakes, and I've noticed that most of the cakes that win the contests are fondant. Is this site only for fondant cake bakers and decorators?
No, of course not. This site is for everyone. Fondant seems to be the trendy thing right now, and it is so versatile that you can do many different things with it that you cannot in buttercream. There are tons of stunning buttercream cake photos out there, but they tend to not be quite as elaborate. Maybe this is why they dont win contests as much.
This site is for all things cake and even cookies, cupcakes, candies, and other things too. Keep looking you'll find lots of butter cream and ganache pictures, recipes, and tips. If it is even closely related cake there will be lots of stuff on this site.