It definitely does, Linux is used by far more people than Ruby on Rails is.
That said, Linux is a huge project with tons of contributors.
RoR: Large number of contributors with relatively small patches, few full time contributors who are paid just to work on RoR.
Linux: Possibly smaller number of overall contributors but supplying more patches each, and more patches in total. More contributors who are paid to work on the kernel on a full or part time basis.
Linux is, perhaps, the most rapidly changing piece of software in existence