Perhaps it's not about seeking "the truth of musical fidelity" for some people. Perhaps for some of us it's more about setting up a system that you love to hear. Or maybe some of us just love to experiment with different things. Or hell, maybe some of us just love music and like the way different things make it sound whether we're being snobby about how we EQ it or not.
Would you deny that you have to experiment a lot to figure out what you really like/want/has that perfect sound signature that displays "the truth of musical fidelity"/can actually afford/etc.? That's how some of us end up with many different pieces in our collections. I have gone through dozens of sets of headphones/IEMs/earbuds/speakers/etc. but currently only use 3-4 of them because those are the ones that work for what I'm trying to hear and do. Which brings up another point.
Would you also deny that different amps/DACs/headphones/speakers are good for different things? I have 3 sets of headphones because I use them for different purposes. I have a set of IEMs that are very good for isolation that I use when I sit in a big room full of noisy air moving equipment all day but still produce a reasonably good sound signature. I have a set of sealed cans that I listen to when I'm out and about or in the office because they sound much better to my ears than my IEMs and I want some isolation for myself and my coworkers. I have a set of open cans that I love but can only listen to in my very rare quiet personal time. I have speakers too, for the occasional times when I'm able to watch a movie or listen to music with my family or just want some background sound. When I can find 1 set of headphones that can accomplish all of that, I'll be forever settled on it, but I just don't foresee that happening.
I also have multiple headphone amps. One of them is mobile (has it's own battery) and I use it with my phone or a PMP when I'm not going to be a computer or other stationary music source because it drastically improves the soundstage, backdrop, and high end detail. I also have a portable DAC/AMP combo that I use pretty much everywhere else these days since I don't have a decent stationary one at the moment. When I get one of those rounded up, wouldn't you just know it, I'll have 3 headphone amps too and I don't feel like I'm doing anything wrong by doing so. My speakers are self powered monitors or I'd have a separate amp on them too (I suppose I do, it's just built in). 4 AMPS!
For me more variety is not EQ as you so eloquently generalized it for me but rather variety means I can enjoy hearing something any time I'd like be it the "truth of musical fidelity" or the best I can have at that moment. Should I go on or am I just confirming that you are right to cast your aspersions based on your own half cocked theories which you've clearly based on broad generalizations? Right? How could After all, we do all want the same thing. Right? anyone want anything other than "the truth of musical fidelity?" Why don't we only have 1 player and 1 DAC and 1 amp and 1 speaker and 1 headphone, etc. that is perfect? Maybe my idea of perfect is different than yours... That's why.
I'm not interested in "the truth of musical fidelity" so much as I'm interested in really loving what I'm hearing when I hear it. If I were an audio professional rather than an audio enthusiast, I might have a different P.O.V. though.