I would say that questions about mobile networking are more properly on topic on Serverfault.
But we deal with questions about actual scenarios from system/network administrators (relevant part of the FAQrelevant part of the FAQ). So for example, I think that "I'm a mobile networking sysadmin, how do I reduce or minimise latency on..." or even "I'm a sysadmin who is getting complaints that our web app times out over a mobile network..." would be on topic.
Your question asked a hypothetical question, essentially "Why is it that...?" and we don't deal with hypothetical question too well here, and arguably it was also asked from the point of view of a user of mobile networking, not a network admin with a problem. In short, if the question was "How can I reduce" instead of "Why is it that..." then it might have fared better.