No that's not true at all. You don't have to be an expert at doing/creating something to criticize it, you just have to have experienced a lot of it. If someone is an audiophile and listens to singing as a hobby, he is perfectly within his rights to criticize someone's singing even if he can't sing himself.
Just like someone who can't cook can complain about a meal.
*sighs*
I'll estate it again, as it seems that my english capabilitites are even worse than I expected.
I'm not, and will never dispute the right of a person to voice his/her criticism about anything, despite his/her knowledge and experience on the matter. You do not have to be an expert to criticize anything. One of my all-time most admired persons is Andrew Loomis, and I abide by his statement that "the layman does not have to understanding anything about art to decide wheter he likes your work or not" (or something among those lines) as an ultimate parameter.
One saying that the echo/delay is overdone, that the rendition is not fitting, that her voice needs serious work, or wathever - that can be assumed as criticism, and I have nothing to do with it. But "ZOMG, she haves hamster cheeks what a attention [censored]" is not criticism, is bashing someone's work just for the sake of it. And this have caused too much damage on this community already. We've lost the opportunity to have access to the work of very productive members for the sake of bullying from people who never added anything to the pool at all besides the casual poop they drop on it. The list of modders and helpful members retreating from the community grows larger and larger, and the trolls are still sticking around.
I'm sincerely not concerned about her ego or wellfare, this is the internet after all, if you're exposing yourself, you had it coming. But this place should have a better attitude toward fan-made creations. That's my point.

EDIT: As this is my last statement on the matter, consider as my response to any further discussions here this one: "NO U!"