I don't know if the Apple II world had more hard core programmers. Keep in mind that Amiga had the demoscene, the PC had those lovely Borland compilers (look at how many shareware programs there are with BGI files, and you will have a good idea of which compiler they used), and if you return to the 8-bit era there were plenty of programming books for the Commodore 64 and other 8-bit micros.

It's kinda funny though, when I look at my library I notice that most of my "serious" programming books are for the Apple II while the "fun" programming books (games, problem solving, or directed at kids) are for the other platforms (particularly the C=64). So if my library is indicative of what was really happening, there was definitely a huge difference between who was doing the programming on different platforms.