I know I just find crits more fun than fury, no matter what the numbers say as to which is better for each powerset (up that even more with the +crit Scrapper AT IO). Definitely more fun to me than constantly chasing fury.
Considering the extra hps and therefore regen brutes get, brute probably would have been the better choice for my kat/wp, but that doesn't matter enough to me. Not to mention that with the lower resistance cap of scrappers, Strength of Will becomes pretty skippable considering I'll already be close to the smash/lethal resistance cap after tough and IO's. I prefer to look at that as being able to take a different power somewhere else instead.
Have to admit it is also fun to tank as a scrapper when it is needed and surprise people instead of being a brute where it is just expected.