It's not a casual thought. I recognize that there are lots of details, there always are, we're talking about computers :)
I don't think it is necessary (or the best implementation) to clone the parent process, in order to maintain important properties like the process tree / container state, etc. I recognize that it's a sorta neat hack, "well if we just start by cloning the parent, then we don't have to figure out what state to include!", but that just pushes the details to the child process needing to figure out what to exclude, which IMO is a worse default.