People did care and people did complain but it wasn't an atrocious design. Everything in that image, I could totally believe any or all of those things come from Adventure Time; except for the eyes on some of them. It was a definite downgrade but it wasn't an eyesore and it was at least mimicking a specific cartoon style.
This Toucan Sam it a total eyesore with a pallet that strains the eyes and even without the gradient schnoz, the color scheme still hurt to look at. From a design perspective, it's like they looked at that Cal Arts meme and used it as a template because "That's what kids like probably." and it's body has no real structure or cohesiveness. It's just a pile of different shapes. New Lucky at least looks like he was built into something with specific anatomy and ideas put into him.
They're both bad, but you can tell someone put some work into actually designing Lucky to match a specific style, they just were going with a style ripping off Adventure Time which really didn't work. Toucan Sam, on the other hand, looks like when a kid learns flash after a week, down to using gradients as a color.
The new Trix rabbit is also pretty bad, but it's new design is exactly the same, just in a worse/blander art-style. There's really nothing to critique there other than 'It's just drawn worse now.' (and it's honestly not even the worse version they've drawn for him) as opposed to the other two drastically changing things and just looking more poor overall.