This is a common problem in almost every field, not just game design!
I work in chemical research, and there are so many stories about projects that get started without a clear focus of what the goals are, what is hoped to be accomplished, what is success. So the mantra I tell younger students who are just starting out-- design and plan the goal before starting any experiments. Because if your experiments work, you don't know what you're doing, so you don't know when you're done running them.
Here it sounds like the same thing. Programmers and artists going to work every day, making things and doing things and working very hard, with no clear focus of WHAT ARE WE DOING.
I make a reccomendation for everyone: know your goals. If things change en route, so be it-- one need not be lashed to the hood of a plan as it careens towards a brick wall, but its better to have one than to keep paddling towards the sun. Pro tip: you never really get anywhere.