Because Snow Leopard is full of unpatched security holes. [0] Including RCEs.
[0] https://wyzguyscybersecurity.com/apple-patched-safari-and-os...
To your point, there are plenty newer MacOS versions that might still suit ones taste, still run 32 bit apps, and still get patched.
There are plenty alternatives to surfing Safari. Heck, you can even get modern Firefox compiled for Power Macintosh G3, G4, or G5 (not for Lion 10.7 or newer, which dropped Power Mac support): https://www.floodgap.com/software/tenfourfox/
iCab (at icab.de) is another labor of love, though release notes look like 2018.
Sites like Low End Mac help find things that can live on (example 2015 article, though incomplete and dated): https://lowendmac.com/2015/what-is-the-best-browser-for-os-x...
> To your point, there are plenty newer MacOS versions that might still suit ones taste, still run 32 bit apps, and still get patched.
Where "plenty" equals "two", sure. Apple releases security patches for the last three Mac releases. So, High Sierra has one year left, and Mojave has two years.
I'd love to do Snow Leopard instead but tracking down old software that's compatible has proven difficult. I'm convinced it's out there—iffy backwards compatibility means there shouldn't necessarily be fewer compatible apps, just different ones—it's just tracking them down in 2019 that's a problem. Mavericks is my compromise.
Snow Leopard for life! The OS and the hardware it ran on, still run that Adobe release now just as well as they did then.
I'm not sure the treadmill has resulted in things feeling importantly different for standard tools over the last 10 - 15 years.