Can I ask why WPMU automatically creates a user account,

Can I ask why WPMU automatically creates a user account, unseen, when purchasing a plugin? And then proceeds to take monthly payments from that users current account?

I've now cancelled the subscription I never requested, and awaiting refund on the charge taken.

I've not seen this tactic on any other premium plugin site, and I have to say, it seems a little disingenuous. The fact a chargeable membership will be created when buying a 'one-off' plugin, certainly is not made clear.

Regards,
Paul.