Unless the state is renewing the lease every time you do non-trivial development work or actually undertaking the development work itself as in Singapore, short leases are a rather significant deterrent from making optimal use of the land. If you think developers hold back from developing land because it might be worth more developed differently in ten years' time, wait to see what incentive "the state will repossess it and everything you've built on it in ten years' time" has...