Yes, it generally is. A skilled player playing casually is going to be far ahead of a casual player playing casually. Some will use casual to solely mean time spent, but you can still be hardcore while only playing an hour a week, and likewise, casual when playing 24/7. Casual/hardcore have multiple definitions based on context, but overall, it is a mindset. A casual player is just playing for fun, doesn't care about learning anything and thus plays poorly with a somewhat random setup while generally relying purely on vertical progression to get past obstacles. They're always going to choose the easiest difficulty when playing games. That is a broad generalization. I consider myself very casual by the first part of your definition, but the playing poorly part does not define me. Neither does the lack of wanting to learn. Your definition here almost offends me as a "casual player" because I'm not like that. As a community, I believe that we need to stop dissecting casual vs hardcore because the definitions are too vague. It makes for poor discussion and debate.