There are some play reading groups that maintain that post-reading feedback must adhere to a strict "constructive" line.
The NYCPlaywrights philosophy is that verbal feedback is unnecessary for a reading - the purpose of a reading is for the playwright to hear their work. But more importantly: the best feedback is to be had by watching the audience respond during the reading. In this we agree with the playwright/teacher Jeff Sweet.
Sweet says, although not quite so bluntly, that the reason it's more important to watch than to listen to the audience is because people lie more with their mouths than with their bodies.
This is not usually out of malice: people tend to soften their criticisms in a public forum like a play reading. And the "constructive" stricture for feedback sessions only magnifies that tendency.
But the truth will out, sooner or later. I've seen promoters of "constructive" feedback in action: they avoid expressing negative feelings about the play, and spout a string of soft-sell euphemisms instead. Then, once the playwright has left the room, they say what they really think.
This is the behavior of politicians, not people who care about art.
Enforcing "constructive" feedback means that dissident voices are often squelched through the effort to reach some kind of consensus and achieve a teaching moment. Sometimes the squelching is done quite deliberately - I attended the reading of a founder of another playwrights group in New York, and in the notes of his reading's program, he very explicitly said, in effect "if you didn't like my play, STFU." He then went on to produce the play, and it was thoroughly trashed by critics.
NYCPlaywrights is not a course in playwriting (it would charge much more for membership if it was) but rather a service for playwrights, to hear their work spoken aloud, by skilled actors. Feedback is strictly optional: the playwright must request it. And when the playwright requests it they are warned: they might hear something they don't want to hear. In this, NYCPlaywrights feedback is no different from a critic's review. Anybody who is serious about writing plays needs to get toughened up - critics don't feel the need to coddle playwrights' egos, or reach a constructive teaching moment.
At NYCPlaywrights, audience members get to express their feelings, in any way that they wish (but only about the play, nothing personal) without any group-think restrictions. This means that sometimes arguments break out, and people disagree passionately about some aspect of a play, or even play theory in general. NYCPlaywrights prefers the expression of visceral honest feelings to namby-pamby carefully-articulated verbiage. The NYCPlaywrights philosophy is that honest emotional feedback is far more valuable to a serious playwright than all the "constructive" feedback in the world.
But some people are by nature conflict-adverse. They find the NYCPlaywrights type of no-holds-barred feedback upsetting. If these people are playwrights they should avoid having their work produced in a public, critic-reviewed forum, and stick to readings of their work for an audience of friends and family members.
And they can join a "constructive" playwrights group and never worry about anybody making strongly-worded, passionate commentary about their plays - at least, not to their face.