Easy. Imagine an asshole restauranteur who kicks you out without recourse every time. Annoying, fuck that guy, but not too bad. Say he owns a few places. Still

Easy. Imagine an asshole restauranteur who kicks you out without recourse every time. Annoying, fuck that guy, but not too bad. Say he owns a few places. Still not too bad, the world's full of competition. Now imagine that asshole owning almost all restaurants and enforcing his fuck-beebman-in-particular policy. Or, say, a bookseller delists some book for ideological reasons. If it's one private location, little harm, little foul. Amazon? Uh oh. Size and market share do matter, and some effects depend on that.