Wow, @Lanx0003 I never thought I'd read such an anti-DIY diatribe on here like that one. I could ignore it, but there's things here to unpack, going from easiest to hardest:
Intellectual Theft
Those projects are just replication of the existing design that the company has fabricated or copied from the manufacturer...
Imagine how cloning Wilson Audio speakers of worth more than 20k, 30k and above possibly damages company's business.
Almost all of the kits I've seen from Madisound, Troels Gravesen, Parts Express, Meniscus are unique. In some form factors it's really hard not to end up with the same tweeter and woofer as someone else because they are natural partners from the same vendor. That doesn't mean the electro-acoustical design was copied. This is especially true in 2 way systems.
Yeah, all those fake Wilson speakers out there really cut into their business .... << giggles hysterically >> because "I was about to spend $30k on a speaker, but hey, I cloned it instead, and whew, the rest I'm spending on women and booze"... is not a real thing.
The DIYers do not really design anything. That is not a hobby but "killing time" only.
C'mon guy, you are seriously going to try to redefine "hobby?" Merriam Webster says you are taking liberties with the language, the definition is very simple and very broad:
a pursuit outside one's regular occupation engaged in especially for relaxation
DIYers in any field have a variety of skill levels and are attracted by more than 1 type of work. I welcome them all. I used to make furniture. By the time I wanted to make my own speakers I lost my woodshop so I had the cabinets made by Lee Tyler. So am I not a DIYer now??
I am not sure what kind of fullfilment or satisfaction they got out of it.
So, based on this, I should say that fishing is not a hobby, because I sure as hell can't tell what kind of satisfaction a fisher gets when there's a perfectly good supermarket 10 miles away.
Mostly what I'm reading is someone frightened that people will build speakers instead of buy them at the store. Sorry that scares you.
Lastly, the DIY speaker field, which is the only one you focused on, is wide open and better than ever. For about $300 you can have a complete measurement setup, and if you are willing and able to spend the time on the math and science anyone could become a speaker maker. I'm one of those, but I'm happy to welcome people getting a start buy buying off-the-shelf kits too. Truth is a lot of DIYers start with kits, or start modding commercial speakers and then learn the rest. Same can be said with DIY amp and preamps and even DACs.
Good for them.