Back in the day (as americans say) we were saying:

{'ul law'}

much electricity

{'ul puS}

little electricity

Then the game changed, and we begun to say:

{'ul vItlh}

much electricity

But what was obviously forgotten was how to say "little electricity".

'ul vItlhHa'.

Here's how I visualize -Ha'. It's like a vector. If you imagine a verb having a direction, adding -Ha' means to deflect it from its normal direction.

So if you imagine jatlh speak as having a "direction of communication," an imaginary direction representing progressing speech, then jatlhHa' misspeak is a deflection from the normal direction of jatlh. If you imagine par dislike as having an emotional direction, the more this way the more dislike, then parHa' like is a 180-degree turn.

-Ha' isn't just negation (that's -be'). Negation wouldn't be a vector; it would be a stoppage of the imagined motion. -Ha' isn't just the opposite. It's a deflection from the normal course.

So vItlh can clearly be imagined as having a direction. Most of us would imagine that direction as upward. vItlhHa' would be a deflection from upward, and for most contexts it would make the most sense to be a turning to downward. Hence, if vItlh is high (in quantity, intensity), then vItlhHa' is low (in quantity, intensity).

-- 
SuStel
http://trimboli.name