How necessary is IPV6 outside the ISP industry?

I work for a company owning a single class C IPV4 range (which we barely use).

Every server (Windows 2008) and desktop (Windows 7) we now commision now defaults to IPV6 (6to4). They work fine but I don't like this unnecessary and possibly unsupported protocol being used internally. (Devices by default respond to pings using IPV6).

There is no way private IPV4 addresses will EVER be a problem on our (or any) private network.

It is recommended by MS NOT to disable IPV6 on W2008/W7 YET it (or tunneling protocols) is implemented by default and causing confusion as we transition to W2008/W7.

We have no need of IPV6 internally - who does? Who is implementing this internally on their private address ranges and why? Why is this default in Windows??

I understand the requirement of ISPs to implement IPV6 for public addressing to easilly alleviate the IPV4 address shortage but I don't understand why most companies with a few hundred (or even thousand) private devices behind a firewall are being forced into IPV6 with Windows builds?

To put it bluntly - every Windows server or client now uses IPV6 as well as IPV4 needlessly by default and MS recommend using and not disabling IPV6 . Why?