just the FAA being a jerk
We don't call them the F'nAA for nothing. Their motto is apparently "We're not happy, till you're not happy."
I spent a bunch of money getting a 2 seat ultralight trainer setup, getting my training credential, etc so I'd be able to be an ultra light Basic Flight Instructor. Got to do it for one summer, then the F'nAA decided that instead of using the homebuilt ultralight aircraft that 2500 instructors had been using successfully for 20 years, that now we could only instruct in factory built ultralights, the cheapest of which run north of $50k, many over $100k. Nobody could afford that.
With the stroke of a pen they cut the pool of instructors from 2500 down to around 170, effectively killing the entry point for new GA pilots. Ultralights were the most active segment of general aviation until that rule change, now it's nearly moribund. Apparently by design. The idea of people building their own planes and flying around freely just gives a certain breed of regulators the vapors. It had to be stamped out.
This is just another example of a regulatory agency gone wild.