[viridian]

Perhaps I'm misunderstanding you, but this seems to more-or-less read as,

"As a product manager myself, I believe that the use of an advantageous market position to strengthen vertical integration is a reasonable practice, so long as the bundle cost of the final product to the consumer remains the same."

The problem with this, and the reason we we anti monopoly laws in general, is that this practice can be self-reinforcing, and allows for the capture of an entire market, extinguishing all competition. This then allows pricing for the good on offer to be set at whatever arbitrary price the monopoly deems reasonable.