It's funny because the US was clearly trying to run up the score in their games too but have had (relative) trouble scoring. They outshot Germany 60-10 and Switzerland 56-9... yeah, that's "sportsmanship" there.
The US players (and I'd love a link to the quotes in question) are just upset that the lack of any credible competition to the NA teams is easily apparent to anyone who sees the final scores - it makes the whole event look as half-baked as it actually is.
And it's the format that has goal differential determine last change in the finals that's mostly to blame. If Canada throws out 5 defence for a late PP to avoid running up the score do you think that's any less embarrassing for the other team? Fact is the Womens hockey is a joke except for 2 teams and the whether canada wins by 6 or 16 it doesn't change the fact that more than half the teams competing don't belong there.