Even though I've been absent, disappeared, vanished, Houdini'd my ass out of class, doesn't mean I'm not there in spirit. What the hell does that even mean? Honestly, it means nothing because feedback is very important in writing, which I've lost out on which is my fault. However, in the past when I had a pretty good attendance record, I was there for quite a few workshops and also because it wasn't my first time at the rodeo. I feel that workshops can really show a writer what they can't see themselves whether it is small punctuation problems or that the reader gets lost from beginning to end (hopefully not). I think that a good writer gets feedback and acknowledges it when they edit.
However, sometimes getting feedback through an online database may be a totally different ball game. The internet gives many people masks that allow them to be whoever they want and since everyone wants to be a critic...well you get the idea. People have the protection of a computer screen which means they can tell a writer that what they write is complete crap or if they have a heart and a conscious they might give some constructive criticism. Point is that if people don't know you and don't have to look you in the face while giving you criticism that will be a way for them to let loose and not have to beat around the bush.
Either way, feedback is feedback and at the end of the day it's your writing.