That was my impression before I worked in the industry, and I worked as a software retailer before becoming a game designer. Chances are you will see multiple game company logos. There are a lot of people involved in making games. Not everyone works for the publisher. Heck, nowadays, most publishers do very little actual game development and rely on a host of developers.
Some developers form long-term relationships with publishers.
BioWare has published multiple titles through us. And so on. During that time you get to know each other. Because sometimes, it's just not easy to make a game. It's a balancing act to make the whole thing work.