You're a teacher.
You ever given an assignment to some students who openly complained that your totally doable task was, like, totes unreasonable and that Mr. SNR is a big fat pillowbiter who hates you and doesn't value you because he totally doesn't respect the workload he foisted upon you?
That's what your average LT having to switch to RT does.
You'll notice when RTs switch over to LT, they're almost always like "yeah, it's something you have to get used to, but you put in the hours, rely on your coaching and I'm good enough to make this work." Meanwhile LTs are like "god this is impossible -- I've spent all this time on LT and they're throwing it away so I have to learn a whole new position -- you might as well be asking me to learn Japanese, you assholes."
I've no doubt it takes getting used to. But it's probably a respect thing more than it is a technically difficult thing.