Well, aside from the addition of the cordless drill to turn the stock, how is this different from cutting cove with a tablesaw? That's a time honored technique where the stock is pushed on a vector against the side of the blade.
I think the devil is in the build. The strength of the same jig design will always be dependent upon materials, fit, build and technique in use. The user in this case is careful to make several low degree passes before he gets to the product he desires - that also mirrors the technique for making cove.
I might also quibble over the ergonomics: I think the critiques made here are spot on because I also would like to see features that move the woodworker's hands further away from the blade, but then I didn't see his hands anywhere near the blade, so maybe I'm wrong.
If the jig is built well and used with the caution we should always employ, it seems very practicable.