Uh... the headline of the article was literally "Solving Rubik’s Cube with a Robot Hand".
Kudos to you for apparently reading past the headline and understanding that the demo was actually about hand dexterity. But come on. The average layman reading the headline is going to believe that what's newsworthy is that OpenAI solved a rubik's cube.
If OpenAI didn't intend for that to be the case, they should have used different words. For example, "Using a neural net to achieve a breakthrough in robot hand dexterity" would actually describe what the demo is about.
Unfortunately that is about 1000x less interesting than "AI robot solves rubik cube". Which is why OpenAI didn't choose that headline, and why people like Gary Marcus are criticizing them for being misleading.