1) If the screen image is bad, you can spoil your eyes.
2) You waste much time while looking through different numerous ads.
3) Very often some interesting shows are on late at night at inconvenient time.
4) Very often the shows are silly and dull.
5) Too many soap operas and few serious educative and interesting films.
pluses
1) you may listen and watch home news as well as world news.
2) you can watch scientific and educational programmes or movies.
3) you may relax watching entertaining shows and programmes.
4) there are special programmes for different people, for example, for those who love to cook, or to knit, or to travel and much more.
5) there are also programmes for people of different age: Healthy Life style for elderly people and for children they show funny cartoons, which they like very much.