Yes, many times people assume that all situations are like. If the situation is one of infidelity, then they might project their situation onto the one seeking advice. But all situations are not alike. And the people involved come to it with different histories, and different ways of interacting. Human relationships are very complex. There is no one size fits all solution. I do think that some posters are so angry in their own lives that they bring that anger to every situation that they see.