This is something that came up during a talk in my research group, which I would like to share, in order to check if someone agrees:
It’s true that I haven’t attended a conference in a while. And my main opinion is that they are mostly not worthy the travel expenses… but that will be a different post!
Either way here is my caustic view of the 3 kinds of people attending a Science Conference nowdays:
The authors of the papers (which usually sit in the front row) and will only ask you a question out of courtesy.
The friends of the authors (well the folks you know, and who happen to be attending the conference that will sit there while you present, before leaving with you to go somewhere else more interesting)
The “Others” which could actually make you a good question but will not. Either because they are polite not to shoot you down in public, or simply because there only there for the free wifi and not really for you paper.