That's the exact problem - if you contrived a date into an int then yes, it is compatible with the =, >, and < operators.

The point of the blog post is to assert that that contrivance is not appropriate in nearly all use cases, despite how popular it seems to be. In the vast majority of use cases contriving MM/DD/YYYY into MM/DD/YYYY 00:00 GMT is not reasonable and can mask a vast amount of unintended behavior.

For example, a person in California who enters a date of 06/05/2022 in reference to their local time zone will suddenly wind up the day before - because 06/05/2022 00:00 GMT is actually 06/04/2022 16:00 PST.

If the developer wants to contrive the date into a "midnight instant", they are welcome to do so and there should be plenty of convenience functions to allow them to do that, but implicitly performing that contrivance is dangerous.