You have a good point. I think the danger comes from the potential for abuse. Once you ship software that has failing tests, you've established a precident and are likely to face pressure to do so again even when the tests are more critical. That's why I'd resist that, at least. My experience is if there's a real problem and later everything in production is on fire, no one cares about the caveats or risks you pointed out.

I do also agree that CI can hide complexity, but that's true of any tool as well as non-CI builds. Compared to a human running things, it's at least somewhat self-documenting due to being scripted.