Yes it is. If I open a .png, and done things to it, and I want to save it, it's because I just want to save a .png. If I wanted to have another format I would

Yes it is. If I open a .png, and done things to it, and I want to save it, it's because I just want to save a .png. If I wanted to have another format I would "import" the .png, not open it. If I want to save something else, then I'll go to the save as... And will choose what I want to save. Having a "save as..." that just gives me the proprietary format and hanging to go to the "export as..." to have other formats is even worst.