Most require more setup to get to that point, either through being a bit more fiddly to set up (eg, the BSDs), or through simply not shipping with a decent pack

Most require more setup to get to that point, either through being a bit more fiddly to set up (eg, the BSDs), or through simply not shipping with a decent package manager (eg, OSX, where the package manager isn't even comprehensive -- you have to manage different software from different places). Sure, with more work you can get stuff up to the same ease of install, but with most Linuxes it's all working out of the box.