People do ask about monitors and headphones, e.g., what should I buy? Therefore, they are included, since they are gear I used for mixing purposes in order to produce what you are hearing. I thought it was pretty straight forward, but I guess not.
I sincerely doubt that a whole herd of people will run out and buy a set of monitors that they heard in a youtube demo simply in order to listen to one song. It seems a little silly to me. Keyboards, guitars, drums and other instruments make sense. Headphones and speakers not so much
Sometimes when a person is looking for a set of speakers, or a new set of speakers, they may ask on forums "what speakers do you recommend?" I will tell them what I use, as will other users. Therefore, if someone watches this video, they will know that I used a certain type of speaker for my composing, mixing and monitoring.