Meh. Fills in the summer months when there's no football.
I don't know tho, actually. Obviously being English (as opposed to French or American, say) has had a part in it for exposure to the sport at an early age purposes, but quite a lot of English people don't give it the time of day, so it has to be more than that.
The length of the conflict appeals, I have to say. Cricket (and I really mean test cricket here) is a game you inhabit for up to five days at a time. The match ebbs & flows and breathes, one sees battles within battles and often just when a game is drifting there's a moment of magic from a champion player that turns things around & reignites the interest.
The history & respect for tradition appeal to the nostaglic son of Albion in me too;
names like Spofforth, Grace, Lohmann or Barnes still have a real meaning for cricket fans that doesn't exist for football fans with association footballers of similar vintage. This is probably in part because cricket is very stats friendly, but also because the game has inspired so much wonderful writing over the years & centuries.