I find it hard to believe this discussion is still going on.
Reviews are worthless as a rule, and the whole system is a joke. 95% or more of so-called reviews aren't even reviews. They're mind farts.
What's sad is that so many readers are guided by those silly little stars. And that they waste time reading that 'review' crap instead of reading the story.
If they bothered to read the first page of the story, they would x) instantly know whether they personally like it or not, y) develop their own critical faculties, z) save themselves tons of time. It takes less time to read a page of a story than to dig through dozens of asinine 'reviews'.
I think the whole system was set up that way so that kids who want to write could engage in interaction. It was never meant to be a serious system, just something to encourage people to get more involved (and maybe watch more ads while they're at it. I wouldn't know, I don't use the app).
So my suggestion would be to stop treating the review system with seriousness it doesn't deserve. I use it solely (and rarely) to encourage kids who clearly have talent to keep going.
And yes, authors definitely should have the right to delete the bullshit masquerading as 'reviews'. But it's probably best just to ignore it.