In theory you can open source software by throwing code over the wall with total disregard for anyone else that may be looking at or using that code. Zero overhead, right?
In practice that doesn't actually work because some users will not respect the boundaries you lay out. No matter what you do or say, some significant subset of users will assert or assume the act of open sourcing code places a litany of obligations on the people releasing the code. Furthermore, some of these people will go to great lengths to try to get you to comply with these obligations. At which point you are either doing a lot of extra work you were not planning on doing to make these people happy or you are dealing with a lot of extra and unnecessary personal drama. Either way, it costs you time and energy that you have to account for.
The only way I have ever seen anyone explicitly avoid this overhead was when no one was using their code.
In practice that doesn't actually work because some users will not respect the boundaries you lay out. No matter what you do or say, some significant subset of users will assert or assume the act of open sourcing code places a litany of obligations on the people releasing the code. Furthermore, some of these people will go to great lengths to try to get you to comply with these obligations. At which point you are either doing a lot of extra work you were not planning on doing to make these people happy or you are dealing with a lot of extra and unnecessary personal drama. Either way, it costs you time and energy that you have to account for.
The only way I have ever seen anyone explicitly avoid this overhead was when no one was using their code.