That’s wrong, though. Snapshot photography is a form of its own. It has some things that professional photography doesn’t have. That’s because, casual and crummy as they may be, snapshots are taken for their own reasons and on their own occasions. Their approach to the world is different, not somehow inferior.
For example, snapshots permit a subjectivity that’s completely out of bounds for regular documentary photography. A snapshooter does not feel the documentarian’s quasi-scientific responsibility to show the world as it is, an objective world that doesn’t have the camera itself stirring up trouble in it. The reason is that the snapshooter doesn’t try to be outside anything. The snapshooter is someone immersed in life who just happens to be carrying a camera. The documentarian is a looker; the snapshooter is a liver. The documentary photographer records an event; the snapshooter is part of it. For the snapshooter, the taking of the picture is probably inseparable from a real-life relationship. So to say that you can’t intrude on others with your snapshot camera would amount to saying that you can’t intrude on others. It’s not nice, perhaps, but you can do it.
A documentary photographer can’t do it. Photos like these are very rare in straight photography.