Except I've seen countless times that users ignore stuff if they can, including important warnings etc. Ideally confirmations should be kept to a minimum anyway (and instead ensure all actions are reversible), but in cases that's not possible I'd rather have a confirmation show in a modal where I can at least see the page/context it's referring to (and it goes without saying, all modals should be draggable, even for touchscreen devices) than a separate page entirely. And if an action can't be performed then I'd much rather see the reason why in a modal window that grabs my attention and forces me to acknowledge it than a button that appears to do nothing but cause some easy-to-miss message show up elsewhere on the page.

I tend to agree. Modals are just contextually different things and even if some/most of your users understand that it's extra cognative load that may not be required for what the app or web page is doing.

Such questions as "if I close this modal is that different from using the cancel button?" should not even need to be dealt with by the user.

I agree, and I also don't think that modals should be used for these things. I merely also agree with the article that these are use cases when a modal "can" be used. It still isn't a good solution, but at least it doesn't actively hurt my ability to access a resource.