Most of the tasks we do are for humans. For example, a tax calculation is counting numbers so the government can pull money out from my wallet, but government consists of humans.
Because of the Turing completeness theory, everything one Turing-complete language can do can theoretically be done by another Turing-complete language, but at a different cost. You can do everything in assembler, but no one wants to program in assembler anymore.
Ruby inherited the Perl philosophy of having more than one way to do the same thing. I inherited that philosophy from Larry Wall, who is my hero actually. I want to make Ruby users free. I want to give them the freedom to choose.
I believe consistency and orthogonality are tools of design, not the primary goal in design.
From the viewpoint of what you can do, therefore, languages do differ - but the differences are limited. For example, Python and Ruby provide almost the same power to the programmer.
I didn't work hard to make Ruby perfect for everyone, because you feel differently from me. No language can be perfect for everyone. I tried to make Ruby perfect for me, but maybe it's not perfect for you. The perfect language for Guido van Rossum is probably Python.
Actually, I didn't make the claim that Ruby follows the principle of least surprise. Someone felt the design of Ruby follows that philosophy, so they started saying that. I didn't bring that up, actually.
