I agree 100% that i would love to see them let go of Goku, and actually let the god damn others have some spot-light. But I'm still a bit meh on pinning it on Toriyama specifically. The dude did incapacitate Goku for 70-80% of DBZ so that we could specifically follow other characters, and it gave a lot of room for Krillin to shine as a fairly intelligent individual in the Namek Saga (and to a lesser extent in the Cell Saga). We also had some pretty amazing scenes with things like Tien holding Cell at bay at the expense of his life, and Piccolo getting huge power-ups (and overtaking the entire cast at that point). And he did build Gohan up to Ultimate.
And I want to clarify, because I keep defending Toriyama lately, the dude's not infallible. He made a LOT of mistakes with DBZ, and he has paid the series shockingly little attention over time (and he is responsible for Tracksuit Gohan. I think?) But judging from how his statements and how he's handled the show, he's fully intended for other characters to take over multiple times. Gohan was MEANT to be the protagonist following Cell; his editor and Japanese fans freaked out. Vegeta was meant to be the focus of Resurrection "F," we know that others stepped in because they wanted Goku to have a more central role. Considering that all he did was provide guidelines for Super, when we line up the anime and manga side-by-side, we can see roughly what he wanted. Doing so, we can see Vegeta was MEANT to kick Goku Black's arse, Vegito is meant to appear, Vegeta loses to Hit, Zeno kills Infinite Zamasu, Gohan is intended to be incredibly important for the ToP, and so on. Actual execution, and how Goku-centric it has been, seems to fall in large-part on the animation studio and Toyotaro. So fuck it, let's hold them ALL accountable.
The above said, we do need to remember that Resurrection "F" was inspired by fan song about Frieza. So, I think Toriyama's involvement is mostly just for shits and gigs at this point.