Are there hardcore runners who need the thrill & challenge of competing against others? Yes, certainly. For others equally hardcore, that atmosphere isn't necessary.
True. If we're talking hardcore competitor, of course, racing would be a necessary component. However, if we're talking more generally of a hardcore runner, racing may or may not be a component at all. I guess I misinterpreted your comments to say that the desire to compete in some way takes away from one's “hardcore credentials” (or something like that).
Yes, I'd say we're probably trying to fit a square peg in a round hole. However, I always see the term “hardcore” thrown around but I've always had trouble defining it myself. Sometimes, I feel like I'm being a hardcore runner, sometimes I feel like I'm being the antithesis of a hardcore runner. Sometimes, I look at someone and think that's not a hardcore runner. Other times, I look at someone and say that's definitely a hardcore runner. I sometimes have thought I wonder what all of this means but it wasn't until recently, when I saw this topic come up in a couple of other places, that I really took time to think about both how I would define a hardcore runner and what I see in people when I say that person is or isn't hardcore. I thought it would be interesting to see how people here would answer those questions.