I haven't got a goddamn idea why cricket is so popular.
Because the Commonwealth is so big and cricket has a huge tradition in these countries. Just look at India; they have a population of around 1.34bln (17.5% of the world population) and if I am not mistaken, Cricket is the favourite sport there - one of the few countries, where soccer isn't #1.
Check table tennis sitting at #6. This is mainly because chinese people are crazy about table tennis and they even have slightly higher numbers population-wise than India.
Same goes for Field Hockey, which then again is a big deal in India and quite popular in a lot of other countries (Pakistan, a lot of western Europe countries).
I am also very surprised after checking this list as I was not expecting these two sports Cricket and Field Hockey on top for me Tennis and Basketball are more popular but this is insane as now these two games doing great for subcontinent as these both very popular here so its worth.