Presumably, what technically-minded Mac users who might switch want and what projects like this are aiming to achieve is to have a high level of consistency and

Presumably, what technically-minded Mac users who might switch want and what projects like this are aiming to achieve is to have a high level of consistency and "one piece design" not just on the user-facing half, but also under the hood, and the various BSDs have more to offer in this department than mainstream GNU/Linux distributions. It might be worth looking at one of those Linux distros that swaps out GNU userland/toolchain in favor of BSD equivalents wherever possible though.