If anyone could repair that "hole" they'd be making millions as a batting coach. Snider was always thought to be a guy who's power would develop huge so there probably wasn't a huge concern about the K's (as I've always said there are two ways a hitter can get away with a big K-Rate, Lots of HR's or a big BABIP. I was huge on Snider when he was a prospect because I thought he'd hit 30+ HR's every year. The power didn't develop and whether it is because of stubbornness, uncoachability or just the swing isn't as good as what was anticipated. He was supposed to be a guy that would kill FB's...turns out he's really not good against any FB, especially up in the zone...and he just can't lay off of them. We don't really get O-Contact rates (contact on swings on pitches outside of the strike zone) until AAA and I understand the triple A stuff isn't overly accurate.
to sum it up, doesn't make contact on pitches outside of the zone, so no sense cutting down his swing as it probably won't help a guy like him. So keep swinging hard and hope the power develops was the plan of attack for him. Didn't work