The selection bias here must be pretty intense, if they are showing Apple with a 10% share of the install base and the MacBook Core 2 Duo from 2006 as the most common model.
If you look at the bottom graph on this page https://linux-hardware.org/?view=cpu_family interestingly Core 2 Duo doubled in data representation solely this year.
I know it's unmaintained now, but SimpleOSX VM defaulted to a Core 2 Duo.
Looks like it's successor also defaults to a Core 2 Duo, though with 2 cores and SMT.
https://github.com/foxlet/macOS-Simple-KVM https://github.com/kholia/OSX-KVM
That being said, just browsing through that site, it doesn't immediately seem like it's this family of Hackingtosh VMs adding significantly to the list or at all.