Except he kept him in A.I. form, and wrote several scenes of him having a Wolverine/Jubilee or Batman/Robin or Doctor Who/companion type type mentorship. Such scenes are part of the appeal of Doctor Who, Batman and Wolverine, and importing that characterization to Stark is a smart play.
That's not to say there weren't plenty of flaws in the details of how he went about this. I've criticized him plenty for the way Riri never seemed to be protecting or avenging anyone, because the villains were bland creatures who never did anything vicious. Also, Jubilee, X-23, Dick Grayson, and Damian Wayne all had psychological issues that made mentoring them an interesting journey. Riri's grief wasn't kept as a living thing and it should have been.
There were flaws in execution, but the idea that Stark should be made more relatable by giving him someone to mentor was at its core a smart play.
Eh, been there done that with the mentoring bit - from Eddie March to Jack of Hearts to Rhodey. If you are going to saddle someone who doesn't really need a kid Robin to play off of, then give him a mature adult, not transform him to Batman, or worse, Dr Who with Adric.