Jungle items being used in lane was the case back when jungle items were first introduced. They were made to be items that gave good stats while also helping in the jungle. Laners bought the items and took camps, or they just bought the items and forced them to be balanced to them instead of the junglers. Vlad had hand in getting the first Wraith Spirit nerfed, Elder Lizard got balanced to Nidalee and Ezreal, and Ancient Golem was balanced to bruisers in top lane instead of the jungle tanks who needed them. The items had to be nerfed to not be the only options laners had, and then they were kind of mediocre in the jungle. Making them jungle-only has been the solution.
As for tying them to smite, that was done because taking smite is pretty much always the better option. I know other things are technically possible, but the loss of objective control pretty much always makes it a worse option. The option serves as a trap for newer players.