The difference here is that Star Wars had been and remains wildly popular over the course of nearly 4 decades. On top of it, Star Wars is an entire universe and has been updated with the (lackluster) prequels, disneys new animated show, and these upcoming films. Even between bouts of films, toys continue to come out, keeping its relevance in tact. When the kids become aware, the parents become aware (again).
Toy Story is one of if not Disney/Pixar's most successful franchise(s). Kids will always love toys, and parents will always want to keep their kids happy.
Harry Potter is a wildly successful franchise, and has a universe of its own, but these niche updates to its lore (the new movie coming out, along with Pottermore) limit their audiences. I believe I know more people in a 5 year radius of my age (25) that know what HP is than I do kids (I worked camps for 7ish years, I have young nieces and nephews, cousins, neighbors).
I am hands down a disney die hard, and am willing to call their faults, but I think Universal couldn't forsee that potter's relevance might not last more than a decade or so. Potter was a frenzy when it was current, but now? I don't really get that same sense of demand.
I don't want to force the thread into a debate between uni and wdw, but that last tangent about potter came to mind when reading your post (and writing mine)