"What if your passion is your day job?"
Then pursue it with a passion.
"I find it difficult to go hard at work and put 100% in and then come home and work on side projects."
Then don't.
"Usually, I'd rather spend time with friends and family."
Then do.
"This seems to disqualify me from a lot of job postings."
If getting the job requires a large time commitment to side-projects, then they're not side-projects. If you're only doing something to count towards some job or other, then that is a cost of that job. If you work X hours per week in an office and Y hours a week at home on side-projects you don't want to do, then you're working an (X+Y) hour week. If that's too much, then screw the job because it's clearly not worth it.
With that said, my hobby is programming. I have a few programming side-projects, but they exist for me because I really enjoy them. When I'm not programming I'm usually reading CompSci papers. That's what I get off on. The moment any of this becomes a chore, I leave it to rot. There are a number of dead projects in my wake, but they fulfilled their purpose; I enjoyed creating them and learned from the experience.