AmigaOs as an operating system carries a lot of legacy cruft along, old layers of software, weird and rough layers such as graphics or the shell. An open source developer would be very tempted to get rid of this cruft.
I don't think you can speak about this in generalized terms as everybody is different and has it's own reasons to do something. Especially for the Amiga case this is not true as you have 'strange' people there like Toni Wilen and Jason McMullan. Guys who enjoy hacking enough BCPL cruft in the AROS68K kickstart so you can boot from the OS3.0 Workbench diskette.
