Yup, I'd agree with that assessment, although warty's excellent posts have pointed out, the shape scales up quite nicely.
Just in case it wasn't emphasised, the khukuri as it stands, is just too small to be a primary weapon at 15-18" long. In comparison, the gladius, the standard roman infantry short sword, is about twice as long at 25-32".
That said, in the current world where the normal military fighting knife is about 12" long (eg. the KA-BAR) or usually designed to be attached as a bayonet, the khukuri has a distinct advantage in reach, weight and intimidation (I believe machetes aren't standard issue in most deployments).
The Ghurkas still have theirs because of their culture and traditions - it just also happens to be a highly effective weapon/tool at the same time.
[Purile schoolboy mode] That's what she said.