I took a second look at the OP and realized one of the misconceptions bothering me was the association of "sandbox" style play strictly with one end of the continuum between hack-and-slash and games including narrative goals. H&S is a player's playstyle (not always a roleplaying style) and achieving narrative goals is also part of a player's roleplaying style.
Let me just clarify: I by no means belabor under such a misconception. The attempted continuum expressed (and in hindsight, I could have been clearer) was between totally freeform play and having a character oriented prepared story. The use of hack-and-slash was not to pigeonhole sandbox play (that's why I used the word "sandboxy", instead of "sandbox"), but just to indicate that higher narrative goals were not a consideration in some of our games, other than "go to a place, kill evil monsters, and take their stuff". It just happens that generally, the hack-and-slash stuff was sandboxy, generally because we were playing without anyone having prepared anything.
If I haven't yet made it clear, I'm not interested in pigeonholing any kind of playstyle into one thing. What I like, what I'm interested in, is the variety. Hack and slash in a sandbox. Hack and slash in a railroady dungeon delve. Character oriented narrative goals in a sandbox. Character oriented goals in an adventure path. Please read the OP in that light -- any definitions or associations are just thrown out there purely as rough examples. What I'm interested in hearing about is just how varied "the old days" were.