Random is what gives the game quality.

You can relate it to the general gameplay of ff8 (or ff in general really)

1) there are physical and magical attacks
2) there are little other techniques and statuses that no one ever uses because the first two are so successful.

1.a) there are really strong player cards that have amazing stats
2.a) there are other cards that no one ever bothers with because the player cards are so successful.

Random is the game's little way to remind you that being able to obliterate everything isn't the only kind of fun you should be striving for. Earning your obliteration through cunning and skill is also worth striving for.