Other than aesthetic, why Deep V's?

the rims used in the paris-roubaix are often 'old-school' open-pro's and other low profile double eyeleted designs if there was some merit in using the deep-v profile on bad roads why don't proffessional cyclists use them?

True that.
If you are concerned about the quality of the roads, low profile rims are your friend. They transfer less shock to the rest of the bike (and you).
Bend not break FTW