rhubarb bolted

No, you didn't do anything wrong. All plants want to flower, it's their natural way but some just don't know their seeds are useless.

Since yours is a long established group, it wouldn't hurt to dig them up, divide, feed the new planting holes and set the divisions back in. But if you want rhubarb this year, I'd wait until early fall to do this when they have the winter to recover.