That metaphor would make sense only if the only place you could by Coke was at the Coke company store. I'm fairly sure there are lots of places that sell both Pepsi tee shirts as well as Coke products.
Let us side load apps, and we'll stop bitching about Apple store practices.
There are lots of places that only sell one, too. Restaurants frequently sell only one or the other, in large part due to anticompetitive agreements when making the sales contracts.
I think the point is something Apple-sanctioned. Most people want to be able to put apps on their phone without violating terms of service agreements..
I think it would actually be fine if they didn't sanction it, and had it violate the warranty (at least), but allowed it (and hid the setting somewhere).
Let us side load apps, and we'll stop bitching about Apple store practices.