Consolidating reasons from other threads into this post, because this is the one change I thought was most harmful to everyone universally and the game as a whole, creating some serious imbalances.
1) Grafts round out missing pieces of profession toolkits. How else is a soldier going to be able to occasionally root a mob? Some professions have no crowd control whatsoever. I can see selectively removing some grafts, either because they're useless, like 1HB Incompetence, or because they are overly profession specific and shouldn't be broadly available, like a calm or something, or they have some specific interaction with a profession's perk setup or other running nanos, like Zazen related whateverage, and implementing it as a graft would be too complicated. What I can't see is soldiers not being able to root a mob every 30 minutes. Anybody else want to tell the thread what you can't do without access to grafts?
2) If old players keep their grafts, but new players can't get them, this creates its own balance problem. Even when new players reach 220 and have all their endgame gear, AI30, all research, etc, they will be at a disadvantage compared to players who have done nothing to merit having a benefit except for playing for as little as a day longer than the aforementioned newbie.
3) Old players keeping grafts and new players not having access to them creates an economy problem. Grafts become another unobtainably expensive item for people to charge increasingly more and more for.
Either don't change grafts at all, or remove them entirely while giving soldiers (for instance) a root to use.