Strongly agree with proton007. Increasingly, I debate the so-to-speak 'morality' of spending ever-bigger hunks of money to pursue incremental improvements. There has to be a balance. A point where each of us says "enough".
I do think a distinction needs to be made though. It relates to finding this 'balance'. I'm fairly sure pursuing excellence in any hobby, even as a consumer, can enhance what we offer in other parts of our lives. By relaxing better in our down-time and developing new skills and insights into (in our case) music-listening, there is a chance it indirectly enriches what we offer to others.
But can it go too far? An obsession that absorbs us so much it takes away from what we offer, like addiction? Obviously it can, but I'd be surprised if most of us get anywhere near this.
I see head-fi as a social "tool" with unique qualities. Typical of internet-based groups, it is a "knowledge-base" which pretty nearly "knows" about every headphone and hp amp in existence (DACs not so much maybe). To this it adds a large group of "testers" - us - from all around the world and many perspectives and skill-sets.
Given time and experience with head-fi it's possible to read our 'test-reports' and get some idea how something will sound to one's own ears - more 'accurate' I suspect than what we get from manufacturer's marketing hype and - in many cases - magazine reviews.
Against this - as we all know - head-fi has its own hype (FOTM, FOTY) which oversells some products and undersells others. I know which hype I prefer though.
There is another limitation to head-fi. Each of us really is unique (ears, preferences, how our brain decodes sound etc) in how we hear. Decision-by-group only goes so far. I was reminded recently it often does not provide the specific answers we might seek about a particular piece of equipment.
Once one reaches this point constantly, one has probably out-grown head-fi - except for other aspects such as Argyris mentions.
(ps: I've been here five years and lurked two years before that, and consider I've posted far too often for what I have to offer I suspect I will be sick of head-fi well before reaching headphoneus supremus status!).