While I agree, OpenBSD also doesn't fully implement features/functionality.
If your operating system only does 20% of what another operating system can do, it's easier for you to have 80% less bugs.
That's not a knock, it's a design philosophy of OpenBSD (which is to do the minimal needed, and no more, in the most simplistic way).
That does not match my experience with obsd. It is not so much minimalism as they are not afraid to reinvent the wheel. A obsd install is full of services, more than most linux installs I have seen.
For example you can imagine my disappointment when I discovered what a pain in the ass it is to get a pflow producer working on linux after doing the first one on openbsd.