What do you think is Microsoft's motivation to justify the "desire" in your rationale?
What you wrote just repeated the same idea; that they "wanted" to do it, that they were "eager" to do it, and with the "desire" to do it, and everything else was just that they have the ability to transmit their data elsewhere (which you also redundantly described as "ability" and "support to do it"). I can think of several reasons it would be undesirable, in terms of their business operations. The capacity to do something isn't the same thing as having done it, and the source in this OP doesn't make the claim that it happened. So yes, it is a leap.
NO, it is NOT a leap.
1. Yes, there is no evidence that kinect specifically has been used for spying (yet)
2. Yes, the kinect has a potential to be used.
3. Yes, Microsoft along with other companies have given information to the NSA in the past.
Before the "evidence" came out that these companies gave these information to the NSA, they were already doing it. YES? yes. So it's not a LEAP, to consider that it has or may be done in the future.... considering the history. Is it "undesirable" from a business operation? YES, why else were these information kept "secret" until it was leaked? They know it's undesirable, and will keep it hidden as long as possible.
The "desire" has to do with business. Obviously no business, plans on giving information to NSA as their goal for doing business. These companies do it because they 'desire' to collect data for themselves (for various reasons). NSA just comes along and request what these companies were collecting in the first place.