BYU sports are not a missionary tool; they’re a retention tool. Having BYU sports as a gateway to BYU-TV is part of that retention strategy. That’s why BYU won’t join the AAC or MWC or a “best of” and why BYU was reticent to join a troubled BigXII.
As long as your tithing donations (and those of people like you) contribute more than BYU sports cost to operate (including the hidden costs of operating BYU-TV and the unsubsidized scholarships), then they’ll be supported. That’s why wealthy Americans matter to BYU sports more than the potential for increased international members.