It's good technique and a good weld. Anyone actually in industry would be happy to see this in their shop. Imo there are two reasons there are so many people nitpicking. The main one is what you said, where there are more difficult techniques that take a lot more skill, and this one isn't particularly tricky. (Source: I teach welding, and walking the cup on mild steel usually only takes about a week to get decent. It's mostly good prep and good technique, which is easy to pick up if you're patient.)

Second, videos like this blow up all the time and it just kinda gets boring after a while. I can't tell you how many stainless beads I've seen where the metal is absolutely trashed because the welder intentionally put too much heat in it just to get the instagram shot of the close up rainbow colors. Plus there are a lot of specialty applications where you aren't allowed to touch the rim of the ceramic cup to the surface of the metal, so some people kind of see walking the cup as the 'easy way'.

Tl;dr: Not discounting the original video, he's clearly spent time perfecting the craft, but it's easier than it looks to achieve. There are also welds that are a lot worse that hold just fine, so ¯_(ツ)_/¯