Do people realize there’s not really a mature set of "norms" for online discourse?  They also don’t give much thought as to how their online habits can be hurtful or rude.  I’ve run into this with people I know "in real life" (offline).  Do we not really care what effect our "etiquette(s)" have on others? People who are quite welcoming in person can,  it seems, rather easily, neglect to consider what they communicate to people online (and how they can engage in  behavior that comes across as ignoring/cold-shoulder).