[matchu]

Ruby offers an abstraction that other languages don't. That doesn't mean that using the abstraction is a bad habit.

I agree that C-style for-loops can be handy, but the prevalence of this shorthand doesn't make it good pedagogy to skip right to it. Not everybody is ever gonna enter the real world of programming, and not all of those people are going to use languages with C-style for-loops, and, even then, for-loops aren't fundamental; they're just a shorthand.