Because it's reasonable to assume that both those guys will play a full 82 games this season, or going forward? I'm not skewing stats. I'm going by their totals. Neither of those two will ever play a full 82 games again. So why would you go by their full season projections?
You mentioned that you think the Datsyuk Helm Weiss line is doomed to fail, and followed that up by saying none of the three of them averages more than 130-140 shots/year. That suggests that you expect the line to fail because they allegedly don't shoot the puck much, which is what Son of a Wing addressed by using a much more accurate shots/game average. Their season totals are that low due primarily to injuries, and to use full-season shot total to predict what kind of offensive output we can expect IS skewing stats (or at the very least is a poor choice of statistical values to use). With your value of 135 shots/year, it suggests an average of 1.6 shots/game, which is much lower than what they actually shoot. His response has absolutely nothing to do with playing a full season.