An off-hand, poor remark may cut deeply but part of the workshops are about finding your voice and how to communicate it, and also to have confidence in it. It doesn't do you any good to put your thoughts and ideas down in a medium if no one wants to read it.
Perhaps the terrifying thing to any prospective writer, let alone someone who wants to make a living at it, is seeing the number of talented writers who can't get (traditionally) published to save their very own lives, or make enough in new media to cover advertising costs. If they review their own writing, and feel it needs improvement, the comparison is itself a daunting prospect to overcome: "If more talented/polished/experienced authors can't get an audience, how will I?" At least with a writing workshop, you know that someone will read your work and give you honest, if biased, review. And knowing whether or not you connect with your audience, get your message across, keep the attention of the audience is crucial; but, also, is answering the question "if you didn't, why didn't you?" For this, readers are often the hands-down worst people to ask as they project their own latent construction desires, but writers can spot mechanical flaws, relate past similar problems and solutions, etc.
A mix of viewpoints is needed.
The risk of crushed passion is likely worth the opportunity for ignited passion.