Homo economicus to the rescue! Every consumer has perfect knowledge, spending power, and access to effectively unlimited choice which is why when they want lower quality things it's a calculated, careful decision weighing all the options and the long term impacts on both themselves and the future of the industry.

Monopolies and pricing power clearly destroy this utopia but even without those I try to remember Pratchett's "boots theory" whenever I start to blame the consumer for "accepting" abuse from the capital in power of what gets made, when, and for whom.