I think the thing here is just a perspective issue. If your focus is the tool, then you want platform agnostic. If your focus is the platform, then you want too

I think the thing here is just a perspective issue. If your focus is the tool, then you want platform agnostic. If your focus is the platform, then you want tool agnostic. For example, if I'm a ruby developer that ends up using different platforms often (osx, debian, centos) then it's justifiable that I want to use a packaging abstraction that's platform agnostic but ruby specific. If I'm a primarily a debian user that happens to program in ruby and a dozen other languages then I would prefer a packaging abstraction that's tool agnostic but debian specific.