I strongly agree with this. When I am doing hobby projects, I can easily maintain my motivation because I believe in the value of the product and I'm working tk implement my own vision. When I am working at my job, I find the architecture and design parts fairly interesting, but I've come to hate the implementation due to either a lack of belief in the product or the overbearing bureaucracy.

Sadly, I have not found a real solution for this at my job. I have tried changing teams, but I usually find similar issues on each - the biggest being a lack of confidence in how the business product owner is handling the system's business process design. So I just carry on, knowing that I'll never get promoted or be a respected part of the system. I've spent the last 5 years in this mindset and it's terrible, but at least I can support my family (what was that quote from Home Improvement... something like 'there's no such thing as a crappy job if you're using that money to support your family').

I think this the main reason people do side projects, so you are in good company. Some lucky ones might turn their side projects into their job.