Let's face it, the writers hate the CMC

Wouldn't it be weird if she suddenly started flying? We probably would've been like: "THIS BREAKS CONTINTUITY!!"

That's an idea for my next question Windwakerguy430.

Since the question was "Are the writers being mean by making Scootaloo still flightless after all these seasons?" my answer would be no. Seeing a pony struggle to come to terms with a disability and having everypony that matters say that her disability does not define her has probably helped many kids struggling with their own disability. It has also probably helped others realize that it is not what a person can't do that matters, it is what that person can do. See, the writers are being kind to the audience.

Personally I would be fine with her learning to fly or not learning to fly, just like Rainbow Dasy. (Although I am routing for her and hoping that eventually Scootaloo will fly high up in the sky.)

Because some people in real life can't always do the things they are expected to do by society. It has been suggested that she may be disabled and will never be able to fly. In a way, I think it'd be nice if they kept it open-ended with her (so that we never find out whether or not she will be able to fly at some point in her life).

The writers definitely aren't being mean to her though. If anything, they're being inclusive.

Let her fly for crying out loud!