My wife and I fly ORD/TLV or EWR/TLV frequently enough that when she's on her own, she only takes the route (or back) on Friday/Saturday so she doesn't get exposed to all this nonsense. As others have posted, it's a rare occasion when this type of request doesn't happen. I don't think Schnit is wrong in saying that the FA can ask, but the comments beyond the ask are a complete load of crap if true and the FA certainly should know better if she's been on more than one flight. My guess is the FA took the easy way and tried to move one person as opposed to 2 or 3 and then dug herself into a hole with the added comments.
In theory, this is no different than family members asking to sit together and the process should include an ask to move to an equal or better seat, otherwise don't even ask. If the PAX says no, the FA should say thanks and let the requesting passengers know that they can try to find other people that are willing to swap with them or they can remove their a$$ from the plane.