While I am sympathetic to the authors, the reason that agile swept over the industry is that it was a demonstrably more effective when measured by business outcomes. "AI slop all the things" is miserable for human employees and introduces new kinds of dysfunctions called out or hinted at in this manifesto. However, if on balance it is more effective when measured by business outcomes, there is little chance of this manifesto gaining traction in the industry.
From my own personal experience, which may not reflect the broader industry although I suspect it does, the ones who embrace slopping with the least regard for their peers are also the ones perceived as the most effective by their employers. Those who take a principled stance get the worst of both worlds. They cannot combat the deluge of slop with their own clanker, and they lose the influence with their company leadership that would provide sponsorship to change how AI is being used. This creates competitive pressure to follow suit, and from there it is a race to the bottom.