Whereas the Beastmaster was a 1/1 for 2G, the Cultivator is a 1/1 for 3GG, but also with Fabricate 2. This means you can either put two +1/+1 counters on him, or create two 1/1 Servo tokens. It's fair enough to make 3 bodies for 5 mana. But what's most interesting about the Cultivator is having the same ability has Wild Beastmaster. Whenever the Cultivator attacks, your other creatures get +X/+X where X is the Cultivator's power. It's relatively easy to pump your creatures by +3/+3 in that case.
While there are currently some decent pump spells in Standard currently, especially in Red, 5 mana is a lot to invest in this card. As it is, Wild Beastmaster wasn't a top-tier card at any point, just a nice way to quickly win games with the beats out of nowhere. Cultivator can do the same thing more efficiently on its own, but It's not going to win out of nowhere the way that Wild Beastmaster could. It requires a bit more set-up, and being on average two turns slower than Beastmaster really hurts its ability to be a competitive-caliber card. It takes what was already a fringe Standard-playable ability and puts it into a more mid-range role that just isn't going to fly in top-level play.
Cultivator of Blades is probably going to be relegated to Commander, where so many other ways to pump it exist. In token-based strategies, Cultivator of Blades is going to be extremely powerful, especially in that he can create two tokens himself. But he's a bit too fragile and too high on the curve to really impact Standard. But I can see this card doing plenty of work in Limited and Commander. While I wouldn't first-pick this in a draft, it's going to be a useful creature to have if you're running a good amount of creatures. It's a solidly designed card.