Just supposing that part of the hobby is buying stuff. I'm unpersuaded that this represents moral decay sufficient to go on rants about it, or be made crazy by it.
There are backwoods timber-cutters (when I lived in Austin, Texas, the term was "cedar-choppers") whose garage holds a $60,000 bass boat, with a 250-HP engine, hauled by an $80,000 truck, the justification for which was towing the bass boat. There are those who catch many more fish who keep a john-boat with a 25-HP outboard by the side of their shed and haul it it with a 20-year-old work truck. The former makes admittedly lame use-case excuses, like, "It gets me to the fishing spots quicker," as if they are professional fishing competitors and prize winnings are riding on their ability to plane their bass boat at 40 mph. Most of the time, the john-boat owner just knows where the fish are and goes there for dinner. But is it anyone's job, other than the guy's spouse, to complain of irrational expense? The guys like him that made that boat need groceries, too. If that's his hobby, and he is fulfilling the other responsibilities of life, then it doesn't seem my job to call him a fool or a materialist.
I collect mechanical wristwatches--surely a useless and expensive exercise if there ever was one. But I admire the workmanship and craft, and I deeply enjoy the research into the history of the companies I collect. I also admire the design, and while I don't cover myself in tattoos I don't mind just a bit of decoration, the value of which only I and a few like-minded friends appreciate. But there are those on watch forums who feel it is their duty to inform me that a $10 quartz watch is more accurate than my nicest mechanical watch (which isn't actually true--I do have one mechanical watch that for some reason runs to quartz accuracy, but I didn't expect it). They talk about how Bill Gates wears a $15 Casio, and Warren Buffet blah, blah, blah. It does make me wonder why they are on a watch forum--it's as if they feel it their job to go on anti-materialism rants on every forum where the participants spend lots of money on their hobby.
There are those who spend tens of thousands on amateur telescopes. Are they doing science with those? No. They are pursuing it just for the rush of seeing that little bit of additional detail in the Ring Nebula or the Cassini Division, or just that hint of purple in the Horsehead Nebula. Are they subject to confirmation bias? You betcha. Is there a cadre of scientists on their amateur astronomy forums telling them that they are wasting their time and money, because nobody does science that way anyway? Probably, but I'll bet not professional scientists, who are also hobbyists when off-duty, if they participate in amateur forums at all.
The only justification required for spending a lot of money on a hobby item is that I want it and I have the money. The problem is not the spending, but the insistence on affirmation. If I think somebody bought foolishly, and have enough personal experience with it to justify that thought, I simply ignore the thread where they seek that affirmation. Or (in the case of watches I don't much like but for some reason feel obligated to respond), I might say, "wear it in good health." But if they ask me about it before making the purchase, I'll give them an honest and complete opinion, assuming I actually know anything myself. (My own rants concern people who eagerly trumpet stuff they don't personally know to be true, having heard it on the Internet from others who are doing the same thing--this is how the boutique products became hip in the first place, but it's a temptation to which those who oppose boutique products can also succumb.)
Rick "listen in good health" Denney