Yeah but PC gamers are a different breed, and typically know what they're doing way more than the console market (generally speaking)..
Consoles are more of a known quantity, and "Sony", "Microsoft" or "Nintendo" on the hardware box represents a seal of quality (up to a point), both with the hardware and the software that will run on it.
This gives uninformed buyers (i.e. grandma - just to stick with a known stereotype) confidence that they're not buying something awful for their grandchild.
Before the pedants jump in, I know this is an over-simplification and there are bad games on consoles, yes yes..
But that's the general idea.. It's like the Apple App Store (minus the sheer volume of available software), it's a walled garden so there's an implied level of review and quality that is supposed to give consumers some confidence about the products, both hardware and software.
Also, less now than before, hardware manufacturers don't make money on the machines, they make money on the licensing for the software.
Console makers aren't interested in making devices that sell at super thin margins and provide zero incremental revenue because they get bought by a homebrew crowd that won't buy into the ecosystem.