I admire adults that spend time with children in a classroom setting. I'm sure that many of the students enjoy the experience.
But putting a NES in a room with children does not make her a teacher and is highly unlikely to significantly improve the children's English language ability, spoken or otherwise.
If the adult enjoys the work and the salary and benefits, good for her.
The problem occurs when the 'school' represents this process to parents as language education. It is not.
It has many foreign teachers. They do not all say derogatory things about EF. Foreign teachers who feel young at heart enjoy teaching kids for fun.
Training centers are not every foreign teacher's preferred employer, but some foreign teachers wouldn't change such a job for any other kind of teaching post.
You should live and let live!