It's usually because someone has seen either my landscape photography work or my camera gear when I've been out shooting. I see what's going on in their heads, and sometimes they even tell me. "You have a nice camera!"
I'll stay out of that argument for the purposes of keeping this short. Let's just say that it has little to do with the camera.
So, over the years, I've done the rare portrait session or the like for friends or family. I always advise against it. The usual disclaimer is something like, "if you want good photos, hire a professional that does this type of work on a regular basis" (i.e. not me). It's not that I don't want to do it. The problem is that I can't live up to what's expected from a photographer that is skilled in this kind of work.
So, my son's cub scout pack wanted to do portraits for this upcoming school year, and guess who was asked :-)
I really don't mind. And knowing that these photos would be used for the online scout messaging and events website only accessible by the scouts, I didn't think there would be high expectations. With the help of a friend and also our den leader, we got it all done within an hour.
My photo-buddy, Wes, has been in the same type of situation many times before. And his response? "My camera does not shoot people."
There's no fooling around. There's no discussion. He shuts down the discussion right away.
Maybe there's some wisdom there :-)