My point more or less stands: there is a sizable audience of mainstream comic book fans who pick up a book every month regardless of its quality, whether it's to enjoy bitching about it without guilt or because they don't want to break up the run or simply because they always have. They reward the company with sales independently of the company's actual commitment to quality in the product.
That's all very true.
But I would point out that sales figures in the comics industry are notoriously fuzzy. Frex there are sales charts based entirely on DM, and sales charts for bookstore sales. Not all charts include both. Different books sell in those markets. Then there's trades - some books do nothing in trades, while others sell like gangbusters. It's a lot more complicated than just measure sales of pamphlets in the DM.