The problem is not with throttling per se (it’s a laws of physics after all!) but not disclosing and/or misleading customers to think there is an unlimited stable bandwidth and/or not disclosing in clear words when, how and how much throttling will be triggered. Do that - and the grief from both sides will be avoided. Without proper and clear disclosure both sides think the other side is an a holes
Are you using "throttling" to mean the same thing other people do? When people say "throttling" they refer to the deliberate/artificial action to that effect, not the natural throughput limitation.