It sounds like the others are encouraging complacency and dishonesty, to the detriment of the art form...well, that's IF those tweets are saying what I think they're saying. No one is "encouraging complacency and dishonesty". They're more encouraging being respectful to your coworkers and being mindful of your place in your community. As well as your future in said community.
Her comments were unprofessional pure and simple. Does she have the right to dislike the show? Of course. But her way of expressing that opinion left a lot to be desired.
I am a firm believer in constructive criticism but there was nothing constructive about her comments. Wouldn't it have been better to say something like "tough first preview. Can't wait to see what happens when they have a few more performances beneath them"? It acknowledges that there are issues but also shows support.
As others have stated - these are people she hopes/d to work with someday. Who in that cast/creative team will ever want to work with her? What producer/casting director will want to hire her?
You take her comments and apply them to any other industry and she would probably be shown the door. Let's not excuse her just because she's on Broadway
"All our dreams can come true -- if we have the courage to pursue them." -- Walt Disney
We must have different Gods. My God said "do to others what you would have them do to you". Your God seems to have said "My Way or the Highway".