What about Harry Potter is family friendly to the toddlers that these rides are not aimed at? My 9 and 13 year old (actual target age for the movies with 9 watching the first couple and 13 can watch all of them) ride all the rides in HP lands except the castle one. That even scared my 13 year old. But guess what? The movies also slightly scare them. The rides are absolutely up to par with the movies in terms of target youth age. They are meant to scare you because the movies scare you. Keep in mind several of the movies are PG-13.
I agree they will never SOLELY look for the families with ONLY 0-9. However, they do need to compete for the larger families with older and younger kids. Which I have seen lately that is where they are going. httyd is a perfect example of a well balanced area with play areas, theater show, family coaster, family water ride, and more thrilling flat ride. There truly is something for every age group in that area. Focusing on re-doing the one kids area in Universal also shows me this and that Pokemon is the rumor (widely popular in the 4+ age groups) also shows me this.
Your argument makes no sense. HP is PG-13 for a lot of their movies so it makes sense their rides would be too. Do you even have kids? Because I can tell you HP is not something real young kids are into at all. Sure they like the wands and the magic of it all, but they do not understand it at all. The books were meant for Tweens to read not kids.
I will also say by the time my son liked Mario he was already 40+ inches tall.