Hello, and welcome to my first UI/UX rant of the year. Please enjoy the complimentary popcorn.
It's not that it's difficult to learn. It's that it's annoying to use every day compared to Axe-Edit, Helix, QC etc. That's really where the "difficult" moniker comes from IMO.
The "move a block" functionality is a perfect example. Helix's way is as simple as a baby picking up a toy from the floor and putting it somewhere else, most likely in their mouth!
By comparison, Fractal's way is how a programmer made it as simple for them to implement, with zero consideration for user experience. It's a list of functions you need to scroll one by one, buried under page 3: Tools in the layout grid. That's been there since the first gen Axe-Fx and in all these years nobody at Fractal seemingly said "you know what, using this sucks, let's make it better!"
That's just the tip of the iceberg of many issues that are in the hardware operation, but don't exist in Axe-Edit. People give Fractal props for quickly fixing any issues with the modeling - no matter how minor - but at the same time there's a laundry list of usability related issues that never get any attention just because it's not of interest to Cliff and seemingly not a concern for anyone in the company.
It's frustrating to see companies that have products that do many things really well, only to stumble on specific points, whether it's Fractal's usability issues, IK's Tonex app/Tone.net, UA's refusal to have sensible features on their pedals etc.