also, a word about curved handles...
If you grab a bowie knife, you are going to grip it differently than a khukuri. We talk about this all the time here, when newbies come back with blisters wondering what went wrong. The ticket always being that when you use a khukuri, you use the pinky finger as a "catch" - against the butt area.
So, perhaps, that is why a straight handle looks foreign to us...because we look at that blade and think about chopping/swinging with it...and using our pinky finger to "catch" and "snap" at the end of the chopping/swinging motion. Can't do that with a straight handle as well.
There is precedent in curved japanese handles. Even ones that "swell" a little...getting larger as it goes back to the butt.