It help that Disneyland has the blessing of size. There’s so much to do, the loss of one attraction just isn’t that big of a deal.
Sure, I liked Splash Mountain, but I also like that I can take the hour I would spend waiting in line for Splash and apply it to taking a grand circle tour aboard the Disneyland Railroad, or join the happiest cruise that ever set sail on “it’s a small world.”
Personally, it also helped I had a chance to ride it before it closed knowing it was the last I would get to.
I’ll never be mature about the closure of Tower of Terror, however. Damn Disney for that bastardization of the Hollywood Tower Hotel.