> but if you make good use of what others offer the inclusion might add value to > the project
This basically never happens. You need someone who knows the code inside out to keep working on it and the person who copy & pasted it is too busy being lazy.
Like how ZiNc didn't support Tekken until MAME did it, there are plenty of other situations where a console emulator won't work for arcade games. If we'd just taken the spaghetti code and merged it in then I doubt anyone would ever bothered.