They already killed leaching when people giving people leech exp got less exp for actually being in a party, even in a total party of 2 and it being a bishop.
With the HS nerf, and addition to Decent HS nodes along with this change, Nexon is just beating a dead horse as many people have started solo-playing this game for years.
I blame that on the super easy leveling and low player count. You can get to 200 on a determined day of 2x exp (which includes the high multiplier stacks) and bypass like 70% of the content created for levels 10-200. Most of this can be done through solo grinding and party content is lackluster due to the nerfs of good PQs rather than the revamp of bad ones.
I first thought it was the ideal way for skills that share the same skill key (such as Buccaneer's Double Blast and Buccaneer Blast, or all of Dawn Warrior's Solunar skills), to be placed in nodes. After further research, I realized that Buccaneer and Dawn Warrior has nodes that combine both versions of a skill into one node slot, so why doesn't Hayato? Sure Hayato is a JMS class and isn't a KMS class but that isn't an excuse to over complicate Hayato's nodes if it ever was one.
TL;DR Dawn Warrior and Buccaneer have enhancement nodes that combine both forms of a certain skill into one node slot unlike Hayato, which has separate enhancement slots for Battoujutsu Stance and normal stance, which I find to be ridiculous and should have those skills merged.