I completely disagree with that line of thinking. One of the best line drive hitters I ever saw was Gary Sheffield. Sheff had 8 different seasons with over 30 homeruns. I think the reason Votto has only done it once is because of how much he walks because of teams pitching around him to get to Brandon Phillips. If Votto had better protection he would get more pitches to hit and hit more homeruns. I mean last year he walked 135 times. In 2012 in just 111 games he walked 94 times. In 2011 he walked 110 times. He's not seeing many pitches to hit.
We only have batted ball data from 2002 onward but from 02-09 Sheffield had a line drive rate of 17.2%. Freeman so far in his career has a line drive rate of 25.1%. Freeman hits way more line drives. Votto walks a lot because he has a good eye and doesn't chase not because he doesn't have protection. And it's not like Phillips or Bruce are poor hitters. Even last year when Phillips did have a bad year he did his best with men on base so walking Votto to get to Phillips was pretty pointless.
Freeman is a strong guy and when he does connect on a pitch like that it goes a long ways. But his natural swing is to go gap to gap like Helton did. But Freeman doesn't have the benefit of playing in Coors all the time like Helton did.