Aftershock change gutted this champ of all he could do now. he went from S+ to B or C tier.
Pyke wasn't "gutted" by anything. He's still an incredibly popular champion who is strong in the right hands. Just because he got a little bit harder to play doesn't mean he was gutted.
I think, by definition, a champion with a 10-12%+ playrate and a 48-49% winrate is actually the opposite of gutted. That's as close to statistically balanced as you can be.
But pyke has this useless health stat conversion. you dont build anything health related ever on thhe champ....
1 - Pyke has two passives. So even if his HP-AD conversion were completely useless (which it isn't) it's not like he's without a passive.
2 - It's not meant to be a gamechanging, incredibly strong passive. It's just a nice little boost when Pyke does buy those HP items so they become a little more gold efficient. Support items offer health, Edge of Night offers health, Black Cleaver offers health, and Dead Man's Plate offers health, all of which Pyke will buy 100% of the time or occasionally pop up in his builds.
edit: And 3 - As DuskDaUmbreon said, it also acts as a leash. The real reason it's there is to prohibit Pyke from thriving in solo lanes or going full tank. Forgot to add that myself.