I think she meant to say that it involves far too little activity or engagement on the user's part for her to call it a hobby. And I'd agree.
I wouldn't. Because then, like someone already pointed out, biking isn't a hobby. Neither is hiking or fishing.
Biking involves plenty of activity and reading is very engaging.
Engaging. To you maybe, but there are people who think reading is boring. And people who believe longboarding is fun. Isn't fun the whole point of a hobby?
Here's a definition for you:
A hobby is a regular activity or interest that is undertaken for pleasure, typically done during one's leisure time.Regular? Check. For pleasure? Check. During leisure time? Check.
Yup, longboarding is a hobby.
Chess and Checkers are intellectual games

I managed to win against my brother and his test results say he's smarter than me - so, yeah... And I've managed to beat my grandad at chess and he was in the Army so

Scrabble, no that takes intellect.
Wait... what? Test? And... army? What does the Army have to do with this?
