You're looking at the 90th percentile, he's looking at the 99th percentile. Claiming things like "everyone uses UTC internally" is obviously wrong when many people just a few years ago were still setting up systems in localtime when dual booting with Windows. Upgrading to ext4 is also not a rare edge case.
Ext4 has been stable for over a decade. It's been a default filesystem on many distributions. It was the default on RHEL 6[1] which was first released over 8 years ago, and the default for the ext variants after that. It's been in use in Debian since 6.0/Squeeze or later[2], which was 2011. It's been in use in Ubuntu since 9.10[3], released in late 2009.
To be clear, your argument is that it's not a rare edge case to have a filesystem that was originally only in common use as the default variant 6-8 years ago or more for the vast majority of installations, which has persisted and since been upgraded?
In-place upgrades do have the potential to leave some non-default options for the final ext4 file system, such as 128B inodes instead of the 256B ones, which is where certain features like reduced timestamp granularity comes in.
In any case, my system was installed from scratch quite recently using native ext4. As others have pointed out and as I linked in the article, it’s likely a kernel issue. I assume many people have the same thing.
It's a Windows issue (I don't keep up with windows so perhaps this was changed in the past few years, but I suspect MS hasn't done so due to back compatibility issues).
