Considering all a thing needs to be a real camera is to be a light tight box......Well hell........Ummmmm.......Damn, that crosses the Holga off the real camera list.
Marko, shoot what you want, when you want. It is that simple. Whatever camera you have at the time is the right camera for the job. SO the answer is..(Drum roll please)...If a Holga is what you got at the moment you want to take a shot, then it is the right camera for the job. If you are skipping shots because of the camera you have at the time, then you need to either rethink why you carry that camera at all or change your mindset.