Are developers excited to develop for Windows 8? And if so, why aren't there more apps in Windows 8 Marketplace?

I am not a developer, but shareholder of MSFT and NOK. Ife veryone is developing for IOS and Android, I can only think that money would be the only incentive to develop for Windows 8. Why am I only seeing some apps on Windows 8 and not others? I know its a Release Preview but then why are some developers developing and not others?