Truth is, no one has the full facts so any reasons as to why this was made the way it was is pure speculation. Only a fool would move to condemn or endorse what is not yet fully understood.
As someone who's implemented custom Bluetooth protocols, it's actually quite easy to condemn an Apple manufacturer ID check to expose custom services.
And what do you mean by "conspiracy"? I would be shocked to find out this was done by some lone wolf and wasn't built with broad (even if grumbly) consensus in the relevant teams. That's how corporate software is built.
Every time someone opens an argument with the classic appeal to authority “as someone who has…” you can almost certainly expect to have that person miss the point of the discussion entirely.
Truth is, no one has the full facts so any reasons as to why this was made the way it was is pure speculation. Only a fool would move to condemn or endorse what is not yet fully understood.