I think bus ticket collecting was chosen as an example by the author exactly because starting a company about it is ridiculous to think about. So we can discuss just inner interest in something without thinking about outer reward.

Probably not... until some unexpected eureka moment comes.

What if bus tickets of certain style correlate to lower accident rates or more reliable schedules and no one else has noticed before?

What if a certain property of bus tickets is a predictor for some other societal result or economic trend in a way few would expect?

What if they are really tasty and nutritious but no one ever tried eating them?

Each one of these is farfetched enough that is no one is getting involved in collecting just to chase these possibilities. But only a collector, motivated by curiosity, is ever likely to catch them.