you keep mentioning a 10 speed trans, the Gen 2 Raptor will have a 10 speed, but they haven't released any towing capacities for the Gen 2 yet so it's an apples to orange comparison trying to take the current Gen 1 Raptor towing capacities and relate it to a non-existent Gen 2 10 speed.
With the current Gen 1 6 speed there's two towing capacities depending if you have a screw or a scab. The scab is around 6k lbs (I forget exactly it may be 6500?), and the screw is 8000 lbs. That's not too shabby, and while it's not the max 11,300 of certain equipped model regular f150's of this current generation, it's higher than even the most towing-capable equipped 97-03/04 F-150.
The suspension is the biggest limiting factor, and possibly the tires (but not sure). I tow ~7500 pretty regularly with my screw and it squats pretty good in the back with the soft suspension, but it still tows and handles excellent, and light years better than my 2000 scab HD truck ever towed. While yes a superduty would be better, I don't have bottomless pockets so I need a multipurpose vehicle and since 15-20% of my driving is towing and 80-85% is not towing, I'm buying a vehicle geared towards what the majority of my driving is, that is still capable at the minority of my driving even if it's not the best one out there for it as long as it's capable of it.
Now I hope the Gen 2's get a little bump in towing capacity with stronger frames, beefier suspension, and 10 speed transmissions so I can step up to an enclosed trailer comfortably. A 10k lb rating would be excellent, but until they release some figures, we won't know anything.