Because starving people will eat absolute garbage, and due to a lack of options, will tolerate it.

Every medium of media and entertainment has become infected and the quality has massively collapsed. What people used to enjoy, now leaves a bitter taste in their mouth. But, since the infection has been so widespread, it's difficult to find alternatives. Since people are reluctant to change habits, and creating, researching, and seeking alternatives is difficult, people are more likely to accept the bad stuff. The degrade in quality, in terms of the people making this stuff, also results in fewer products being released, which results in the people becoming starved for it, so will be more willing to accept the bad stuff. A starving person will almost never turn down terrible food.

This limitation on products, much less good products, has become really apparent in gaming, and even moreso in specific genres, like RTS games, which used to be common and almost universally great games back in the 90s and 00s. But, this phenomenon goes way beyond gaming.