Since you're the tyre expert that seems to know all about rubber I'm just gonna have to take your word for it then. But just to touch on something. Do you think ANYONE could make tyres that can do qualilaps for 60 laps straight?
Pirelli makes tyres to the specification of F1. Simple as that. They have a certain deg in mind. Pirelli makes the tyres to match that.
And if you can't see how the USGP 2005 problem would prevent two tyre manufacturers i just don't know what to tell you. Maybe watch the race and let me know how much fun that looks. And if that's a situation you want to repeat.