Why there are no tennis courts in Dubai big parks such as Mamzaar Park, Mushriff Park, Zabeel Parks, etc?

We have been trying to find a free tennis courts in dubai public parks but we only find one - Satwa Park which is overcrowded with players specially at night (bec. its a single court). But we wonder how come that they did not build tennis courts in their big parks such as Mamzaar, Mushriff, Zabeel, Jumeirah Beach, Al Qusais, Al Quoz, Rahsidiya, etc. etc. where there are lots of vacant spaces. We only see empty football & cricket grounds. I really wonder why?