Some teachers (and probably parents) have had enough of the "whatev-ah" response. Even preschoolers are saying it. The word sort of stops you in your tracks and makes you think that whatever you are saying must not be important.
It's a catch-all response which can mean many things, commonly "I don't care", but also "this is the end of the conversation" or "say what you want, I've got no position on this subject".
For some it's a humorous retort (replaced by fingers and thumbs in a W-shape for the non-verbal version) and a new addition to the slang lexicon, but for others it's a depressing symbol of an alienated generation.
Now teachers say they have had enough because it's constantly used to challenge their authority. In a survey conducted by the Association of Lecturers and Teachers, nearly seven out of 10 teachers said they had heard pupils using it.
"Whatever" does sort of put an end to a good conversation, but if it's not that word, it will be something else. Saying "So?" with a perfectly timed roll of the eyes used to be the ready response and is still used by some students. To me, the best way to deal with "whatev-ah" is to ignore it and just keep on going. It can only stop you in your tracks if you let it.