Nothing is stopping people writing desktop applications. Are you just annoyed that people are choosing cloud services out of convenience?
No. My fear is that they end up trying to implement the "cloud" in anything and everything just because it's "cool", no matter the consequences.
Just imagine: Windows depending on the cloud to work, Linux too, Eclipse refusing to work unless you have a connection all the time with a cloud, Photoshop or GIMP refusing to save your images in any other place than a cloud, Word or LibreOffice refusing to save your files because you are offline. Everyone embarking on the cloud hype without worrying about what happens when you lost your connection.