i don't know about marketing, but things are much more simple, when everything is running on the same machine. There are fewer points of failure, ipc latencies are significantly lower, you are looking at the same system clock (unless you are looking at rdtsc, which is core specific). It's not quite the same, in practical terms.

We got some of the distributed aspects, when we got multiple processor cores and multiple cpus, but it's still not exactly the same thing.