Are there really people who believe those things? Author's profile says Houston, TX which means they should know all about multiple timezones and DST at least.
#3 ("more countries than timezones") author should have known that, given that he is in the US which has 4 timezone.
In fact this list seems much like the original: take any programmer and challenge him to come up with counterexamples and it'll likely be a breeze, but give him a task anywhere adjacent to the concept and the falsehoods will be very easily assumed and encoded into the result.
It's not literally about beliefs, but about the logical chain of nuanced considerations you must go through to implement time. You only "believe" them in the sense that when your hands hit your keyboard to write the first draft of code, you will likely write code that assumes multiple of these misconceptions are true. Hairy problems always seem simpler on first glance than they actually are.
On the other hand, UTC-3 has 8 countries in it, which more than offsets that. Even EST (UTC-5) has a whole bunch of countries in it, including Cuba, Jamaica, Brazil, et. al.
Yeah, a lot of these seem pretty obvious after doing even some amount of work with timezones. Or in the case of #7, it's pretty obvious to anyone who a) lives in a country with DST (which covers a large swath of North America and Europe) b) knows what UTC is.
Countries in North America are very big though, and time zones can be shared between multiple countries (e.g. US and Canada). Just because we span a lot of timezones here, I wouldn't be confident to say, especially thanks to the eastern hemisphere, there isn't more countries than time zones. A timezone is a big, vertical slice that hits a lot of countries, I would have just as well believed there was enough overlap to have more countries than time zones.
#3 ("more countries than timezones") author should have known that, given that he is in the US which has 4 timezone.
#7 and #11 describe author's timezone
this list seems pretty made up.