The problem is not that your premise is too complicated for others to understand, it's that the 'walled garden' is a trade-off which people disagree about.
Walled gardens are safer, and usually have some implicit or explicit quality guarantee (like the Nintendo seal of quality).
Open platforms allow for more flexibility and innovation by new entrants.
On top of this disagreement, we have the meta-issue of whether business model innovation should be allowed; the USA generally permits new business models, whereas European governments are more restrictive.
Walled gardens are safer, and usually have some implicit or explicit quality guarantee (like the Nintendo seal of quality).
Open platforms allow for more flexibility and innovation by new entrants.
On top of this disagreement, we have the meta-issue of whether business model innovation should be allowed; the USA generally permits new business models, whereas European governments are more restrictive.