Why was Mr. Toad's Wild Ride removed from MK? Any reason other then creating Pooh?

[Master Yoda]

I would agree, but from what I understand, it still remains incredibly popular at Disneyland.

But this all leads to my confusion that I've had for years. The Magic Kingdom is far bigger than Disneyland, yet over the years, whenever a new attraction at Magic Kingdom is brought in, another is brought out. Disneyland doesn't seem to have this problem. And given the traffic issues at the MK, from a higher level, this makes absolutely zero sense.

Disneyland is a very different animal from MK.

Disneyland's largest demographic still remains the local nostalgic AP holder/superfan. That segment is shrinking a bit, but it is still a significant part of the number of daily turnstile spins. They largely want the park to remain static with only pluses to existing attractions and seasonal events. Since they are the ones buttering Disney bread, they get what they want.

WDW largest demo are pretty much run of the mill tourists who have little more than a passing knowledge. If attractions are not popular they get changed or switched out for one they think will be. Attractions they deem too expensive to operate can simple be shuttered for years before they get demolished and replaced.

Disneyland re-purposes or replaces attractions just like MK does. Wikipedia lists dozens of attractions, shows and parades that have come and gone over DL's 60 year history. The Huge Star Wars expansion will be built on the ashes of Big Thunder Ranch and portions of the Rivers of America.