Why there is no project role scheme in Jira ?

[Ramarao Gaggara {Appfire}]

Could you please explain me about the reason for not adding 'project role scheme' feature in Jira. I believe 'project role scheme' would help lot of customers to use within their Jira projects.

[Nic Brough -Adaptavist-]

There's no use for it that I can see.  The list of roles in a Jira system is not really expected to go over a dozen or so, even in systems that has tens of thousands of users.