I got a new 2013 Blade Unibar and I find it much harsher on my hands than my old Naish bar. I like to ride with my thumbs on the same side as my fingers but with this bar it's causing trouble.
Maybe it is not the bar, but you that has to get used to it ?
Meaning, some bars ARE horrible in this respect, I agree - but if you have ridden for years with one type of bar, and suddenly change to a new one, your hands are not accommodated as this will take some time to get used to and develop the right "touch" and skin.
So it might go away over time (and it might not)