Because you know what? Regular-ass, unadorned, zero-specifications cheese pizza IS lovely. It's high time we, the enlightened, reclaimed the good name of cheese pizza, not as the last resort of the excessively finicky and the unimaginative, but as a true work of art. A cheese pizza is pizza distilled to its essence, a centuries-old culinary art expressed in its purest form. End of argument.
But since we're here, let's continue arguing.
The "how can we top ourselves next" food culture we live in (of which my place of employ is certainly guilty of perpetuating on occasion) fuels a "more is better" mentality when some things are just best left the fuck alone. Milkshakes are glorious just the way they are. The world did not need "freakshakes."
But even a more conventional, sparsely topped pie is still distracting from its essence. There's something to be said for a simply seasoned steak free of any distracting bearnaise, or (arches eyebrows) A1, or (stares disapprovingly) ketchup. If you only enjoy scallops that have been wrapped in bacon, you don't really appreciate scallops. Similarly, there's a flavor epiphany that the trinity of crust, sauce, and cheese can only deliver if unobstructed by clumsy interlopers to the party.
While we're talking about those interlopers, topping quality and value vary wildly depending on the establishment in question. Sometimes they're perfectly respectable. Tasty, even! Other times you paid $3 for the honor of having some disinterested high school kid sprinkle your pizza with rubbery, fragmented "mushrooms" that look like they should be cleaned up with a Dustbuster rather than consumed intentionally by humans.
Also, every time you order one of those "garbage" pizzas where the cheese is overwhelmed by a haphazard avalanche of toppings that don't even really belong together or every goddamn animal product on the menu, somewhere an Italian nonna cries.