Was Dk:Tropical Freeze's Difficulty the main reason it did not sell that well?

[MTZehvor]

EricFabian said:
no it sold bad because it was on Wii U

Basically this.

The previous Donkey Kong Country title sold over 6 million units, and was probably even harder than TF. If difficulty or stagnation was the reason, Returns wouldn't have sold anywhere near what it did