Slinky is weird in that it is generally themed poorly and all critiques about it are right, but it has rave reviews with any person you ever talk to.
I’ll talk to lawyers and other professionals about their Disney trip and they’ll glow about “the Slinky ride.”
On the topic of slinky dog, I think the draw is that it's an outdoor coaster at a resort not known for outdoor coasters. There are five, maybe five and a half, depending on how you count Tron: Big Thunder, Barnstormer, Seven Dwarfs, Everest, and Slink. Of those, Big Thunder is awesome and iconic, but Barnstormer is a true kiddy ride, and Seven Dwarfs is too short, while Everest doesn't appeal to families.
Slinky Dog is the first outdoor coaster at WDW to give high-up arial views while being accessible to families with children. It also has a fun launch sequence that isn't too thrilling but has fun flashing lights that make kids smile. But more than that, it gets you up close and personal with a beloved character from a beloved movie, and he talks! It's a ride vehicle that talks!
It's popular because it offers fun views from the sky while being accessible to families,
and it's also a character experience!
While I agree it may be too lightly themed, the "Andy built a roller coaster kit in his backyard and attached Slink to the track" idea doesn't really offend me, and seems like a decent justification for building an outdoor roller coaster in an immersively-themed area. What are the other options -- a runaway train? They already did that. Twice.
Now Tron's outdoor section, on the other hand...
