Chances are none/few of the people on the train were Londoners as such (who many are blaming on this thread), they wouldn’t be using such a train to travel around London.. Much more likely that they lived in an outlying town and travel to/from work.
It’s not the most considerate thing to do, but given the bloke sat next tot the bike looked blotto, he probably wasn’t thinking too straight. Rather than being outraged as the news report suggests I’m guessing the other passengers were probably more bemused and thought “bless him, let’s leave him alone”. Chances are he’ll have needed the bike to pedal the long way home after waking up at a station 5 stops past his.