However I still would like to understand why the answers changed. And more importantly, what remained invariant between the art of programming then and now.

After all at some point the question of what is effective programming practice becomes a psychological question about modes and means of human comprehension. And humans don't change that fast. Criticisms of goto in the late 60's are still on target today. Justifications of it from then are less so - because with experience we have learned how to express with exception mechanisms what then we only knew how to say with goto.

So an understanding now of (human) invariants is knowledge that is likely to age fairly well. Which is hard to find in computing. :-)

However I still would like to understand why the answers changed. And more importantly, what remained invariant between the art of programming then and now.

I'd hazard a guess that what changed was access to the data.

In non-OO code, since you've got direct access to the data its easier to roll multiple actions into a single sub. With OO code, though, the driving sub can't do that, so it calls into methods on the object to do it, and generally when people write the methods they make them single-purpose so they're reusable.

What you get is essentially another level of indirection--rather than a sub that looks like:

  code to do A;
  code to do B;
  code to do C;
[download]

you end up with:

  object.method_to_do_A;
  object.method_to_do_B;
  object.method_to_do_C;
[download]

since people seem to be more inclined to make methods do less stuff than they are to make functions do less stuff.