Here the decisions have already been made and can rarely still be corrected.
Yes and no, because that only applies to the respective OP. In public forums, however, the questioners and discussants are only the tip of the iceberg and are numerically far outnumbered by the silent readers – who, moreover, are not assessable for the writers due to their lack of own statements.
Every "oh dear" directed at an OP is therefore always also a "please don’t imitate" to the many silent readers whose children have not yet fallen into the well. From the introduction threads, one can often gather that even those silent readers who eventually do register were often invisibly on board a whole year before. In this respect, I take the (big word) "responsibility" towards the silent readers just as "seriously" as the fact that I would rather be considered unfriendly by an OP than pat them on the shoulder for botching things.
Note always under the premise that every layperson is allowed to "claim" the privilege of being a layperson. That is a widespread delusion to imagine or to pressure oneself into thinking that one must come to the architect with a finished plan; i.e., it would be as if one came unwashed and uncombed if one only had a scribble or a wish list with them.