Always is a bit of a stretch but I'd say it is the overwhelming major reason.
The specifics of the work (whether you code in X or Y etc.) might affect you but that's dependent on your personality and even then not to a big degree.
People on the other hand are much more intense. They can make things much better or much worse. They can also amplify or attenuate good things. e.g. It's hard to enjoy working on your favourite language/technology when you have to pair program with an annoying engineer with a micromanager looking over your shoulder. It's much more pleasant to code in a language that you're not particularly fond while pairing with an intelligent and interesting colleague.
The final line is the people themselves and that can be improved a little through hiring practices. However, an active effort to keep the company culture "good" is also necessary and that has to come from the top.
Reminds me of a blessing from an old boss of mine "May all your problems be technical." Those are the easy problems to solve.
The specifics of the work (whether you code in X or Y etc.) might affect you but that's dependent on your personality and even then not to a big degree.
People on the other hand are much more intense. They can make things much better or much worse. They can also amplify or attenuate good things. e.g. It's hard to enjoy working on your favourite language/technology when you have to pair program with an annoying engineer with a micromanager looking over your shoulder. It's much more pleasant to code in a language that you're not particularly fond while pairing with an intelligent and interesting colleague.
The final line is the people themselves and that can be improved a little through hiring practices. However, an active effort to keep the company culture "good" is also necessary and that has to come from the top.
Reminds me of a blessing from an old boss of mine "May all your problems be technical." Those are the easy problems to solve.