Some are really intentional to get the maximum out of their ad exposure. As for shows, it depends on what ad sponsors also want as they pay for premium rates. Television companies have prime time slots, know those times have more viewers and charge much higher advertising rates. Most of the prime time slots are during the hours of breakfast, lunch and dinner. Those are the times when televiewers tend to focus attention on TV while preparation of food, while eating and after the meals.

There are some conscientious television stations though that they forewarn viewers of possible undesirable graphics to be shown or has something gross in its nature. This gives time for viewers to change channel or switch off the TV for awhile. But, most of the time we don't do so because we are curious on what or how it will be. We only complain about it when it really is disgusting. That's how some people are when their curiosity has been aroused.