Most likely old folk(tm)
I used Arch during the migration from init to systemd (2009-2013). Oh boy did things like to go boom at unforeseen moments. Like random segfaults after package updates, disappearing as suddenly as they started.
But admittedly after ~2013 Arch stabilised extremely compared to before. I remember having discussions around 2014 with people surprised that they didn't have update-introduced issues with their Arch install for 2 years at that time. Most of them never again until today.
Also: new users
After aforementioned stabilisation period I got to know recently started Linux users who just did wired shit. Like accidentally deleting all kernel images on a Luks encrypted system or using unusual hardware which by chance Ubuntu or Fedora supported out of the box but would require kernel patches for Arch.
They wanted to learn and they did learn but always perceived Arch as "more complicated" than the alternatives. But most of that was imo not the fault of Arch.