The random generation of ability scores seems to be one of those fault lines that divides even the old school gaming community, with plenty of people willing to argue its rightness or wrongness, as I recently discovered. And it's an old and active fault line, probably going all the way back to the dawn of the hobby, when someone decided he really wanted to play a magic-user and complained bitterly to his referee when he rolled a 5 for his character's Intelligence score.
By the early 1980s, there seemed to be two "solutions" for this "problem." The first, pioneered by Superhero 2044, was a point-buy system that abandoned randomness entirely. This is the mechanical birth of character creation rather than generation. The second solution is to "handicap" rolls for ability scores in order to give PCs an edge. Take, for example, this table from FGU's Space Opera, first published in 1980:
TSR's own SF RPG, Star Frontiers, opted for a similar approach to generating ability scores, although, unlike Space Opera, it not only ensures that PCs are well above average but that they are not typically too far above average:
Gangbusters. In fact, it's the exact same table.