Ultimately this guy should have had the mind to shop around more for other professors who motivate their work better. Maybe do some experiments? You're not stuck with one advisor, and it isn't unreasonable to think that it's your job and not a convenience, or someone else's job, to find good motivation for your work.
He didn't want to do experiments. He wanted to chase the holy grail in theory. He was full of himself. He didn't want to be Hamilton. He wanted to be Newton. Hamilton was brilliant and amazing and changed the world. I would happily settle for being Hamilton.
When I finished the experimental work for my degree and was working on the thesis, the lab with its 10 KGauss magnet and other equipment was assigned to the next graduate student.
One afternoon we were hanging out in one of the grad student offices, when one of the guys had a problem - his desk calculator stopped working. After doing a bit of troubleshooting, it turned out that the wall plug strip was dead, the breaker had been tripped. We went searching for the problem and discovered that the new experimental physics PhD candidate, while hooking up a power supply, had wired a switch directly across the ac line and turned it on.
Back in the office, with the breaker reset, we were having a good laugh about this. The fellow's supervisor wandered in and leaned against the wall, listening to us.
After a while, he said, "You know, I had to stop him from doing it two more times."
I heard later that he moved into theoretical physics.