Not pretending to be anything. Obviously, I'm a fellow user, such as yourself.
If there is a stated policy, somewhere, that verifies whether or not this limit is controlled solely by Apple or because of a joint agreement between Apple and the wireless carriers, fine. Feel free to provide such documentation.
Until then, it is speculation.
You asked James to supply some form of proof. Until he provides some, or you provide proof contrary to his claim, then you are both speculating on whether or not such a policy even exists. And even if proof of the source of the policy is provided, then discussing said policy is also against the terms of this forum.
My first comment was that the 'whys' of any policy are beyond the scope of this forum. And that's perfectly accurate. This forum is for technical assistance. Other than confirming that, yes, 100MB is the cellular download limit (for whatever reason is actually irrelevant), that's the only technical part of this discussion.
You were the one that first claimed that the terms don't prohibit speculation or discussion of Apple's policies. And I replied by providing proof, linking to the terms of this forum.
Both the speculation (without proof, it remains a speculation, and not simply a statement) of why this limit is in place, as well as dicussing the actual policy, are both prohibited.
I've remained perfectly cordial and polite, throughout this conversation. You, on the other hand, have not. If you don't like someone pointing out a breach of the forum rules, then don't breach the rules.
The technical question has been answered. Why this limit is in place is irrelevant; it exists.