You're spot on (ex casino worker). There's no conspiracy. Speaking for myself, I was nice to people because it made me more money in tips (also, because I am not an a-hole). Made a lot of "friends" when I worked in the casino, employees and patrons. It's not any different than folks I work with in tech (i.e. some you connect with and have genuine friendships and some are work friends). They likely stopped calling her due to upper management telling staff to not engage due to legal liability (or they lose their job).

edit: Additionally, there are whales and there are folks who's job it is to get them in the door (we had game managers for the big games).