[plt-scheme] Is R6RS useless for PLT?

Hi,

I know that PLT has r6rs implementation, but it doesn't look
like PLT community cares much about it.
Isn't it more logical to encourage writing new modules/libraries
using r6rs ? PLT has a lot of specific extensions which can be
added on the top of r6rs and at the same time *serve* as new standard
proposals. IMHO, this strategy can have good effect on scheme
evolution and language learning threshold.

Is it just matter of the huge legacy codebase
or am I missing something?

--
Bohdan