some unix source only has to be recompiled with a larger than normal stack and minor disk and video tweaks.
Then why there is Firefox for Windows but not for Amiga? Why there is GIMP for Windows but not for Amiga? Why, oh why there is much much more Linux software available to Windows than Amiga... Conclusion: your reasoning is flawed. Linux and Windows are more close to each other than Amiga is to Linux or Windows.