Why should I use obsolete hardware?

This is more a consequence of the kernel developer's policy of tying drivers to kernel versions, so that you can't use new drivers with old kernels without lots of (dangerous) backporting work. Debian understandably want to offer well-tested kernels, and due to this policy they can't offer more recent drivers for hardware which has no others available.

Note that this comment is not intended to condone or to condemn this policy, merely to draw the connection with Debian's hardware support.