There's no dismissal in the GP's post. They were merely stating that pretending that some project X is an island is off-putting (and it never is one), and that

There's no dismissal in the GP's post. They were merely stating that pretending that some project X is an island is off-putting (and it never is one), and that by claiming that it is, you put some readers already familiar with the field in a defensive mood rather than ready to read about something new.