Just in case you don't know, the person you're replying to is the author of the blog post, and they mention in it that being stressed out by (potential) unexpected large bills is something they are aware of.
Although even then, "we will only threaten to charge you $100k without meaning it" isn't much of a reassurance.
Getting charged is not the same as paying those charges. I'm willing to bet real money that all who, in good faith, went and asked not to pay those bills ended up not paying them (if they didn't ask, that's a separate issue).
From that point of view, the cap seems more like a common-sense self defense feature that the cloud provider would want to implement. But we have cloud providers in this thread saying they don’t want to implement caps, so, I dunno.
From my technical understanding from a few friends who may or may not know what they are talking about, the caps issue has to do with the processing delay between billing events being emitted and understood. That by the time the billing events have been processed and action taken, the damage would already be done in all but the most extreme cases.
Secondly, the best solution is to simply stop everything. But now the customer has to cold-start their entire infrastructure, which may actually cost more than paying the bill.
Thirdly, it is likely that customers will set a billing limit and then forget about it years later. Suddenly, they've got a complicated infrastructure setup spanning the globe. They finally hit a scale where they hit their billing limit that they had completely forgotten that Bill configured in their early days (who doesn't even work there anymore). Suddenly, the entire global infrastructure is shut down in the middle of the night.
