I think we are reading different things into the term 'sponsoring' here.
Sponsor != Owner
as far as I can tell, the sponsorship here consists of paying one developer out of many. That's good, but that's hardly taking control of the project.
I could setup a monthly donation of $10 to Kubuntu (or to a Kubuntu developer) and I would then also be a "sponsor" of Kubuntu.
This would be like saying that RedHat needs to have control of the Linux trademarks and branding because they contribute so much development effort to the Linux kernel. They may be the single biggest contributer (at least for most kernel releases), but that doesn't mean they control the project.
In fact, from what I remember from the 'who contributed to version X' articles, the contribution from redhat to the Linux kernel is very similar to the contribution from the one developer that Blue Systems is going to be paying for to Kubuntu (and even that ignores the fact that 99% of the packages available in Kubuntu are never touched by the Kubuntu team because they are the standard Ubuntu packages)