Well also, the reason these debugging interfaces are shipped enabled is probably due to a risk/convenience/benefit calculation made by Intel et al, with a view

Well also, the reason these debugging interfaces are shipped enabled is probably due to a risk/convenience/benefit calculation made by Intel et al, with a view toward making repair or diagnoses cheaper or satisfying OEM factory requirements. So in this case the risk is passed on for any number of reasons, not all of which are to the detriment of consumers. Some perhaps to their benefit. From the corporations' point of view, there are multiple customers to satisfy for each device shipped, not just the end user. My point being that this risk analysis is simply more complex than any single end user's needs.