The struggles a director has to go through.

While watching this video I couldn't help but think the issues a director has to go through. The movie is the director's vision and I believe the actors have to bring out the vision on screen. But we see so many instances where the actors demand changes in the script to make it suitable for them. Oru comedian eh ivlo demand pannum pothu, oru tier one star eh convince panrathu romba kashtama vishayam tha.

What do you think about actors meddling with the script?