>I strongly disagree with you in turn. What you said holds true for every genre. There are always anime from the same genre that take an approach that differs from the norm and thus one that's meant to capture a new demographic. You've got comedy shows for kids and adults, romance shows for kids and adults, mahou shoujo for kids and adults. Saying mecha is not a genre because both Mazinger and Evangelion exist is like saying mahou shoujo is not a genre beause PreCure and Madoka exist. Anime from the same genre can tackle completely different topics and target various demographics; this doesn't discredit them as a genre.
A genre best represents the narrative's type, things like Action, Romance, Drama, Comedy, Mystery, Thriller, or Documentary.
Elements of the story, such as setting, plot device, plot structure, should really be considered their own thing, and are better represented as an element, NOT a genre. Examples would be Mecha, Mahou shojo, harem, fantasy, Noir, three kingdoms, and Sengoku period.
For good measure, let me add that neither elements nor genres are Demographics.
Please understand that this is more of a semantic point, as the word 'genre' is so nonspecific that there are currently several "genres" that both overlap and conflict with each other at the same time such that the name of the "genre" doesn't tell you anything as far as whether or not one will enjoy the show. For example, magical girl.
Even 20 years before Madoka, there was a strong disconnect caused by calling mahou shojo a genre. Magical Angel Creamy Mami and Pretty Soldier Sailor Moon demonstrate this quite well. One is Action with fights and beams, the other is a drama involving idols and singing. They both share transformation scenes and magic, but aside from that they are as different as can possibly be; a person who enjoys one generally won't enjoy the other (to the same extent), as their narratives are so different.
My comment wasn't so much that the report was grammatically incorrect when they referred to robot as a genre as the way the current use of 'genre' is flawed and the concept is much better conveyed as an element.