I personally work for myself, and I have found it to be very rewarding and fulfilling. It's not for everyone, but for for some it is certainly far more rewarding than working a 9-5. Especially one where you feel like you have to turn off your brain for 8 hours which I find to be very unfortunate.
To some extent I agree with your mentality. I don't think we should treat work as anything other than that - trading your limited time for money. But you spend so much of it on this thing, work, that turning off your brain to engage in it seems just depressing.