A huge portion of people who sign up don’t make it to level 2 and a large portion of them don’t make it to level 3. See: Wanikani Users Distribution by Level
By the time you get to level 3, you already lost the large majority of anyone who isn’t going to continue. I’ve pulled some irl friends into WK and the only person who even got past level 1 was the one who already knew the kanji anyway.
I think the fact they offer any free period at all is quite nice, so I’m quite happy with it as-is.