He played 20 games with Luke Glendening. He played with a terrible 16/17 Dylan Larkin. When on the same line with AA and Vanek, his defensive play has let that line work. He's been fine.
also he typically gets a lot of his points from the powerplay which has obviously been terrible here so that has an effect on his numbers as well
he'll be fine,probably not for his whole contract considering his age and it's length but as for the immediate future such as next year i'm not particularly worried about him
as for Abdelkader and Helm yeah those are brutal but then again they always have been,some of us have been saying for years that his numbers were an illusion brought on by an inflated shooting percentage and that he would crash down to earth in an ugly way sooner or later
you don't take a plug that flukes his way into a 23 goal season with a shooting percentage double his career average and give him a 7 year contract that goes well into his 30s based on that with a corresponding cap hit to boot(well I guess Ken Holland does but still) that's a David Clarkson type move right there