Not going to argue over water changing... people all have different ways of being successful in the hobby.
We as people THINK we are doing the right thing naturally, and so we try to influence others to do what we are doing. Sometimes this leaves us not open to entertaining both sides of an argument. The thing about knowledge, is that the things we know are constantly being disproved, so that is why it's important to be willing to accept new information, or if not analyze it thoroughly.
As Jes suggested, I would be much more inclined to listen to a person who has done both side by side (water change/no water change) than someone who says "this is what I do and it's right and you have to do this too." I do think it's good we have some of you non water changers on the forum, lets newbies listen to both sides and decide what's right themselves. . Nevertheless, the forum has "norms" and it can seem we're all against you at times.
Anthropomorphizing is a huge issue at times, but I would not keep fish without it. It is fun to set up little scenarios and make up personalities for the fish but you must remember that those two goldfish are not really in love, your betta isn't really a total narcissist, and the pygmy gourami are not really hiding something from you in the back of the tank (ohhhh kay... maybe that's just me.)
Do fish feel pain? Honestly, from a scientific standpoint, we don't know.
Even though they are vertebrates, they are a much lower form of vertebrate (because it took less evolution to get them to where they are), with a less developed nervous system than ourselves. Here
is an article published by Dr. Rose on fish pain. Not the most recent one, no, but last month he published a new one that basically came to the same conclusion (these are reviews, so he is basically going over a lot of other people's research and trying to put it all together).. What's the answer? Well, he wants to say "no," but he knows that'd be incredibly foolish to do, so he's stuck at "maybe." We have just as many great scientists that have good arguments that fish do feel pain.
Okay, so let's assume fish don't feel pain. This leaves us free to abuse them to our will. A very attractive thought, no?
Hundreds of years ago, it was "PROVEN" that higher animals like dogs and chimps do not feel pain. That's right, proven. Abuse levels were unbelievable, just for the fun of it in cases. Dogs were just robotically responding to stimuli, after all. Fast forward, and we prove that dogs do feel pain (though it can still be debated). "Oops."
So, if it's all fine and dandy, and we "prove" that fish don't feel pain, I don't believe this opens up a window for abuse. Fairly recently we thought people that were completely paralyzed also had no conscious mind or thoughts and were unaware of the outside world. Long story short, that was proven wrong as well, but the damage was done.
Personally, I don't think fish feel much if any pain, but I will be open to accept the fact that they do if the time comes that we are able to prove this. I'm just going to keep doing what I think
is best for them. Right now, it's just a little extra comfort when you see a sick fish to believe there isn't much going on in there.
This is one of those posts that I normally type out but never send, but what the heck I'll let you guys have at it this time..