I'm agreeing with you that there are many reasons why the music Industry doesn't share stems but also concluding that many among those could be rationally considered gatekeeping by various groups. I'm not disparaging the industry as a whole or the individuals who comprise it, but the reality is simply messy. Many signed artists I'm sure wish they could distribute their stems or more of their process, but are hindered/prevented from doing so by labels. Seems close to what gatekeeping means to me, but that's just like my opinion, man...