It really depends on the person, thats great you recognize that you do well in the corporate world. Unfortunately in many places the company would own your spare projects due to the intellectual property assignment rules in their employment contracts. Beyond that some of us strongly dislike conformity and being a replaceable cog in the corporate machine. Connecting with one's customers and seeing directly how what you build helps them instead of dealing with corporate politics is a huge improvement to me.
I feel much less replaceable, since I have rights. You can say "nope" to your boss. You can't do that to your customer if he's the only one paying your rent this month. And the smaller you are the more others will push you around, not because they are mean but because they don't have to think about you, and just like you they are tired and barely get done more than 80% of what they want to do. And in some cases people are really parasites and will suck dry everything that's too weak to fight back.
This definitely depends on a lot of factors. If you do work where you are easily replaceable sure. Most software developers don't have anything special rights wise as so few unionize. As an independent developer if you choose work in niches where the demand is greater than supply you can fire your painful customers anytime and move on to other ones. Different solutions work for different people.
