How comes this sub is so small?

F1 YouTube channel has 1.7 million subscribers and Instagram 5.4 million followers and the subreddit has 479 703 subscribers.

MotoGP YouTube channel has 1.2 million subscribers and Instagram 6.4 million followers. There's a big following happening there, so why not here too? it doesn't seem too active either.

F1 YouTube channel has 1.7 million subscribers and Instagram 5.4 million followers and the subreddit has 479 703 subscribers.MotoGP YouTube channel has 1.2 million subscribers and Instagram 6.4 million followers. There's a big following happening there, so why not here too? it doesn't seem too active either. http://ifttt.com/images/no_image_card.png