Back in the day, most of the "old-timers" here had only "sticks in pots" or mostly inferior nursery material to work with. Thirty years ago, a "finished" tree was, by today's standards, pretty amateurish looking. There were virtually no Japanese-educated established instructors--although there were a handful, but you had to live near one to really take advantage of it (this was pre-Internet). There were also only a few serious yamadori hunters getting good stuff from the wild. There were one or two bonsai-specific growers (Brent Walston at Evergreen Gardenworks for one) Again, you had to deal with these sellers on the telephone for the most part. When the World Wide Web and dial-up access began to speed up communications, things began to change--dramatically--for bonsai, IMO.
I remember getting a scanned photo image of my live oak and big cedar elm on my computer in 1996 or so. It was a game changer. I saw (in two D) what I was buying and what was actually available, instead of having someone describe it to me over the phone.
I digress...Circling back--the Internet has allowed folks to leap ahead in terms of access to better stock, instruction, pots tools, etc. I don't think people think about that enough. Sorry to sound like an old fart, but do you Internet-raised youngsters know how long it took to even locate a Japanese-imported "finished" tree before the Internet made this stuff as easy as a Google search? Such searches began in the backpage nursery ads in bonsai magazines, a telephone call and possibly even a site visit. That's how I got to know Zach Smith waaay back when. His ads in the print BCI magazines and ABS Journals had always intrigued me--"Southern bonsai from collected trees" with a drawing of a wisteria...Called him while on vacation in New Orleans one year. Went to see his collection in person. You had to be a member of BCI or ABS to get those mags. WIthout them, you were completely at sea, alone, wondering how to do bonsai.
The "finished tree" thing is a relic of that past, as (IMO) it was a mark of the "you have to do it yourself or it's not authentic" bullshit of the pre-Internet era. No one had "finished" trees since the vast majority of the stuff being worked on was still pretty raw, since bonsai was mostly only thirty years old in the U.S. Since then, demand has been met with supply from a growing number of sources. More people are importing trees, there is a substantial reservoir of high quality collected material, nurseries are growing actual advanced bonsai stock and yeah, SOME of that intial stock worked 30 years ago is still around (mostly in need of re-design)...That "do it yourself" point of view is wearing blinders in a world where endless possibilities are all around. It's limiting and cramps learning. Sure, develop your own trees, but realize you have options...