Attendance is meaningless since the tickets were sold. I won't say they don't care at all about attendance, but the ticket itself is the vast majority of the profit they expect to get from most fans.
Same thing in baseball. With the expanded post season, 162 games is double what's needed for a competitive season. But MLB is having no issues selling season tickets. Even cheap seats are approaching $100, so what's your estimate on the average price? Multiply it by roughly 45,000 tickets and it's easy to see why MLB isn't even thinking about reducing the regular season that they've made almost meaningless with the expanded playoff format.