What would you suggest I do as a music teacher? Tell them they can't overcome their limitations? Tell them they can't become a great violinist like Itzhak Perlman? There are a lot of "can't dos" and closed doors in the world of the arts, but they should never come from a teacher.
"Saying that someone needs a nudge would be like me saying sure, you can sing in the same range as Caruso, Domingo, Carreras, or Pavarotti if you just practice enough...and you're a bass." Not sure this makes sense, why would someone try to encourage a singer to be a tenor if they're a bass? This is most definitely not what I meant by a nudge.
All I know is that my job as a musician and teacher is to make music to the best of my ability. I look up to Jascha Heifetz and strive to be like him, but I'm never going to be like him... I can only be the best version of myself. It's my job as a teacher to get my students to think past their limitations, that's what teachers do. If your child was taking lessons with me you better believe I would try to get them to do the best work they were capable of. You would never hear me tell you "I'm sorry, your child has no talent and no capacity to learn this instrument." It'd be one thing for someone to say this to themselves, and a complete other thing for a teacher to say this to a student, agreed?