To the OP - what if someone has zero interest in building a PC, managing settings, configuring stuff, updating drivers, and all of the additional work that goes into owning and using a PC for games? Can they still be a "hardcore gamer?"
I plan on building my first gaming PC this year, because I decided all of that stuff actually sounds pretty awesome. I have always enjoyed hobbies where you get to build and customize something, and where tweaking, optimizing, and regular maintenance are part of the experience. The fact that I can get better performance from all of that (relative to a console) is pretty awesome. The fact that there are fewer and fewer console exclusives (and that trend will likely continue) and that games are often cheaper on PC will probably mean that more of my gaming gets done on a PC once I have one.
But I totally get people that don't want to deal with that stuff and that don't understand how anyone could enjoy it. And a PC can never 100% replace a console experience (and vice versa).
I don't think "hardcore" is necessarily a positive or negative descriptor. As has been discussed earlier in this thread, I wish I had just said "enthusiast" because it carries less of a bragging connotation, which I did not intend.
But to answer your question more directly, well, yes. Actually I do think the people who are really into a hobby are the kind of people more prone to enjoy customizing their experience, getting hands on, and gain a better understanding the underlying parts of their hobby. As I indicated with examples in the OP, this is generally true with other hobbies. I had a friend in high school with was a skater and he was really into customizing his board and exited when he got some new high quality ball bearings. I have another friend into model trains and he has designed his own custom town surrounding the train. It literally takes up half his garage. Even hobbies that do not grant this ability generally still cultivate an interest in the process. People who are into guitars, for example, can often tell you a lot about the history of the materials used by Gibson and how the production process has changed.
This doesn't mean people who aren't interested in is stuff are not as "cool" or anything. As I said in the OP, there are areas in all our lives that we just dip our toes into and are casual consumers in those areas. But I do think the kind of people who visit gaming message boards regularly, the kind of people who spend a lot of time talking about and playing videogames, are the kind of people who would generally really dig the experience of building their own ultimate gaming system and learning more about the underlying parts. They are generally the kind of people that would find that process rewarding and interesting.
Are there outliers for whom that doesn't apply? Sure, there are always outliers. But I was speaking in general. And that was only one of five reasons I laid out for why I think the platform should be a staple for gaming enthusiast. You'll notice that I never said anything in the OP about forgoing consoles nor did I try to turn this into a console vs. PC fight to the death thread. That unfortunately just happened. I was just laying out all the reasons PC should really be considered an invaluable platform for an enthusiast.