They give us constraints – budgets, deadlines, predetermined styles. Every deliverable is a little bump of approval – client likes it, keep going, great job. We savor the feeling of making progress toward a finite deadline.
Personal projects don’t have easy constraints. We can walk in circles, spending months noodling and researching and testing and putzing without finishing anything. There is no one at the finish line to tell us what a pleasure it was to work with us. There might not be a finish line at all.
Without doing our own investigations and drawing our own maps, we remain foggy to ourselves. We don’t have original conclusions of our own and so are always unsure of what we want from our work.
To my mind, this mirrors perfectly the dilemma all other creators face, too.
One of the reasons it's surpassingly easy to write and market genre fiction is because there are so many functional examples of how to make it. Most of what gets made in any genre is a near-mirror of what already exists in it in some form, because that's what audiences and creators are trained to look for.
This doesn't make genre fiction bad as such; it just means the deck is inherently stacked against making something original with it. Not because audiences are dolts, but because creators don't always train themselves to step incrementally away from the models they patterned their work after.
I like the term "original conclusions". To my mind, it implies that any work we undertake — any story we write, any picture we draw, any program we assemble — is an attempt to answer a question we have. The more personalized the question, the better, since that's where the most personalized answers, the most original conclusions, also come from.
None of this means you can't be entertaining or fun. Beanworld and Jeff Smith's Bone and Groundhog Day and Beastars and tons of other things are both entertaining and meaningful. But they all pushed at their respective envelopes a little. They didn't settle for cleverly remixing their immediate predecessors. They came to their own original conclusions.