Magnitus: However, in most games, there are laws of diminishing returns with stats so you usually don't want to put all your points in a single one (usually, but not always).
That's not always the case.
In Final Fantasy 10, for example, physical damage scales with Strength cubed, while magic damage scales with Magic squared. As a result, the higher the stat, the bigger the bonus from getting another point. (This is also part of the reason why offensive magic is pointless in the postgame.)
(Speed is somewhat odd in FF10, as there are certain breakpoints where one point makes a huge difference, but then you can get a significant difference without any change.)
Or, we can look at Advanced Dungeons & Dragons, which has some really strange rules regarding stats. There may be no difference between 6 and 14, yet the difference between 18 and 19 can be massive (it is with Strength, which also has those weird "exceptional strength" rules).
I could also mention something like Chrono Trigger's Magic Defense. Magic Defense is a percentage reduction; the difference between 10 and 11 likely won't be noticeable, while 99 means you take half the damage you took with only 98. In other words, increasing the stat is more useful when it's already high. We also see that with physical damage reduction in Stranger of Sword City, where it's likely not worth optimizing until you can get it close to the limit of 90%.
bler144: Edit - but yes, in the context of when Wasteland was made, initiative does make more sense than frequency of action. That said, if ranged resolves simultaneously, does speed have any value at all, or is it only useful for melee?
I believe it's only useful for melee in Wasteland.
Your characters can do lots of damage in melee, so enemies die quickly if you can get to them; the problem is that getting close enough to enemies that use ranged attacks can be a problem, and even then you still get hurt (and possibly knocked unconscious) before you get a chance to act; no amount of Speed will allow a melee attack before the enemies get their shots in.
bler144: I think the value depends on the larger mechanics. In an older style game, or even a modern single-turn structured game, yes having 2 attacks where everyone else gets 1 is a big swing.
But in a more real-time or continuous-turn structure it might only translate to a 10% increase in frequency of attacks, so the tradeoff of an attack that hits 10% harder vs. 10% more actions may be less clear which wins out - whereas for a support character more actions probably shakes out as the clear winner.
As Jorev notes, it's hard to say whether this is inherently good/bad, but how it is balanced within the scope of the large game mechanics.
Incidentally, in games with Wizardry or Dragon Quest style combat, there are situations where you might not want high initiative. For example, if you're fighting a boss with a strong multi-target attack, and you have a strong multi-target heal you can use each round, you're better off always acting after the enemy rather than sometimes before. (SaGa 2's late game bosses are examples of this, and in the original version, due to a bug there's no way to consistently outspeed the last couple of bosses.)