First, as already pointed out by others, the Mac was really a graphical system. The Finder was the shell.
But there were other tools, too. E.g., ResEdit for manipulating program resources (I customized many programs using this, back in the day), eventually there was also an enhanced version including an assembler/disassembler. Also, there was the Mac Programmer Workshop (MPW) including all the developer tools, and it came for free. And inside this package was finally the MPW shell, a true shell for the Mac by Apple. (But this was now quite the other way round an indirect access to the machine.) It should be noted that the MPW wasn't available for early Macs, since there wasn't room to do actual programming. Commonly, the LISA (or "Mac XL") was used for this.
[Edit] Moreover, it was amazingly simple to change the configuration of the Mac, especially with System 7 and higher. Just drag things in out of the System Folder and you had already set up the system to your exact needs.
But there were other tools, too. E.g., ResEdit for manipulating program resources (I customized many programs using this, back in the day), eventually there was also an enhanced version including an assembler/disassembler. Also, there was the Mac Programmer Workshop (MPW) including all the developer tools, and it came for free. And inside this package was finally the MPW shell, a true shell for the Mac by Apple. (But this was now quite the other way round an indirect access to the machine.) It should be noted that the MPW wasn't available for early Macs, since there wasn't room to do actual programming. Commonly, the LISA (or "Mac XL") was used for this.
[Edit] Moreover, it was amazingly simple to change the configuration of the Mac, especially with System 7 and higher. Just drag things in out of the System Folder and you had already set up the system to your exact needs.