Canada being 1st is not a shocker. As the host country, they're kind of obligated to send in their A-team to make a large impression, even if this is a lesser games than the more glorious Summer Olympic Games. The US have athletes that don't want to risk injury so they can compete at worlds and be ready for the Olympics next year. Just look at gymnastics, a Canadian female won the all-around competition, while they won silver in the team event. Both US men's and women's team won the gold, but over on the lady's side you don't have the big names competing at all. Over on the men's side, you have at least 3 that have competed internationally, and Sam Mikulak, who is normally a pretty strong competitor, won the all-around by only 5/100 points. I'd really like for a US to host a Pan Am games soon so A-list athletes would be more likely to participate and annihilate the competition.
As for beach volleyball, maybe everyone is waiting for it to get to the quarterfinals and finals. I know if I'm going to spend money for tickets, it's going to be for one of the more important games.