We all meet our ends alone. It stands to reason that they be individual, while we do, indeed, all reach them. But it is nice to have company as you arrive.
Indeed, if arrival is the goal. Certainly we can only achieve the best results when we practice with those of like mind about what results we seek.
Furthermore, Mountain Boy: There are many paths to the top of Loma Prieta.
A common allegory, however, I think it can be very misleading.
For one, not everyone is interested in getting to the top of Loma Prieta; some may be more interested in a different mountain, sometimes a very
different mountain with a very different environment. Climbing Mt. Everest will lead to an entirely different experience than climbing Loma Prieta, and while there maybe be useful comparisons, not every element of such different journey's are comparable in a useful fashion.
Furthermore, as commented by Mr. Hazen, some may be merely interested in the hike itself and could care less about arriving at the end of the journey.
Personally, the top of any mountain I've ever climbed or hiked (metaphorically or literally) has at best been only the halfway point in my trip and usually not even that; more like a "vista point" on my particular journey which I cannot imagine ending other than one way.
I think this expectation of arrival might just be the reason why some drop out of training, often after just making the first step (shodan). They expected to arrive somewhere and were surprised to find out that the journey was just begun.