[Night Fury]

In my opinion it just depends on the situation.
It is all about their intent and also I feel sorta the age and maturity of a person also takes part in it.

I do feel if someone traces that it isn't completely their art and that it isn't good enough for a portfolio.
Art based off a copyright also isn't for a portfolio either.
However, I do feel tracing can help with their development and control over a medium, like pencil, pen, charcoal, paint, etc.

Sometimes while working with kids they sometimes start with tracing but then they tend to move away from that, at least the ones I worked with... and you can sometimes see improvement
which also depends on how much time they put aside to draw

As long as it isn't a crutch for them and they don't claim they did it all themselves

It's hard to comment to some of my friends about art... because they just color other people's pictures... at first I was surprised and wasn't to happy because they tried to pass it off as their own... ... so it can be disappointing as well