I also have a problem with this.

If it really is the case that every single passenger dimmed their window, then there really is nothing you can do, but I also know for a fact that some crews deliberately and repeatedly dim windows during daytime flights.

I do not know if crews think they will have less work if the wholecabin sleeps or if it’s to aid heating or cooling, but I do. Know that on my last daytime flight from CAI to LHR that my window dimmed at least 5 times during the flight and I had to undim it myself each time. On daytime flights I do not wish to sleep and do love to look out the window. I hate it on the Dreamliner thatcontrol ove my window is given to the crew and that they can even lock me out of it. The once that did happen, I called the SCCM to object and my control was only begrudgingly restored.