Strikeout isn't definitive it's subjective at it's core. It's a definitive result, but so is a run saved in UZR. Granted there's more leg work done in the latter but it's something that has a calculable value based on results. And I don't think any "stat heads" blindly follow WAR. We use WAR because it's the best tool we have. If you have a pickaxe to break up pavement, are you gonna cry because something not yet invented (jackhammer) doesn't exist and keep using your hand and a rock, or are you gonna use the pickaxe? WAR is the best stat we have for player comparison. You can disagree with it but you choosing not to use it is your choice. You act like no one knows what goes into WAR but we do. Do you know all the data points? No you trust the stats a bit, just like you trust an official scorer to knwo when to score a hit or an error, or the umpire to know a ball from a strike, or when a runner steps on a base before the ball gets there or not.
There are issues with defensive stats. WE will at some day know more and have more accurate defensive stats. That being said, it's far and away the best method we have for evaluating defensive plays. Positioning plays a part, bias can play a part, but at some point, all of that will be wiped out. We will know how far a player had to travel to make a play on a ball that was travelling at a certain speed and flight trajectory. But what you're bitching about is noise, not a root cause. And players have better or worse seasons. It happens. Escobar in 2012 was not as good as he was in 2011 or 2013, he was also not as good in 2014 as those years. Players have up and down years with the glove, unless you're Andruw Jones. We saw it with Simmons this year. While last year he was a vacuum who made all the plays. This year he booted several balls or had balls slip under his glove that he made plays on last year. It happens. It's baseball. Defense is not as forgiving as offense. You strike out in one AB that's bad, if you boot a routine grounder, that's worse. SS of all positions is where defensive metrics are pretty much the most accurate as they make more plays on the ball than anyone else. Again there are some issues with any defensive metric, and the thing that statisticians do is consider all stats when evaluating a baseball player.
I'd really be interested in your evidence that defensive stats are not highly accurate. I'd love to see the extensive studies that you or a reputable peer has done. Other than OMG look at fluke seasons! Cause guess what, fluke seasons happen, with hitters and defenders. THere are things that don't calculate into stats that are noise. For example, Michael Bourn was much better with Jason Heyward and Martin Prado next to him than he was at any other point in his career. Probably because he knew he had less OF to cover and could play more aggressively. There are non-calculable factors to defensive metrics that are factored in, but that doesn't meant they're not telling a true story. There's factors to hits and walks and strikeouts that aren't calculable, but we still accept them for what they are.
Heyward indisputably recorded more outs than in any other season of his career. He had 365 putouts and 9 assists, recorded as fact results that even you wouldn't admit didn't happen. his previous high was a similar valued defensive season when he has 331 put outs and 11 assists. His high from the seasons before that was 235 putouts and 5 assists. Players have better years sometiems than others. You also make it sound like Gordon and Heyward don't consistently put up excellent defensive seasons. Now I'll give you I'm not into buying Gordon as a I am Heyward because I think LF is one of those positions where thereare some truly pathetic defenders and Gordon benefits from that. According to RZR pound for pound Gordon was better last year than this year, more OOZ and higher RZR. He just had more balls to make plays on and likely his competition was much worse (don't care to look that up)
That being said, what Gordon did compared to his peers in LF is a fact. Whether you agree with it's valuation or not.