Watching serials for entertainment is a different thing. The problem occurs when you're hooked into it.
When you set the habit of watching TV serials everyday, you'll start feeling lonely when you don't get to view it. You'll feel like it's a part of your life, and without it, you'll have hard time living your life.
When I was a kid, I used to watch lots of serials and TV channels. It was my daily routine. If I had to live a day without TV, it would be very painful. I'd only travel to places where I could watch my TV shows.
If I could watch those channels or shows, I'd feel at home. If not, I'd suffer.
After TV serials become a habit, you don't live in the reality anymore. You start to live in the virtual world. When that happens, you are basically escaping yourself from your reality.
To some extent, it's fine until here. But the problem starts when you don't get to watch your favorite TV serials.
Basically, when you watch your favorite TV serials, you will have huge emotional spike on your body. Because serials are designed to make you feel strong emotions.
If you stop watching those serials, you won't get those storing emotional spike which your body craves for. And when you don't get those emotional spikes, you start to create that virtual reality in your existing environment.
You will start to create drama in real life unconsciously like in those TV serials to gain that emotional spike which your body wants so badly. And by doing so, you'll completely destroy your own sense of reality.
It's a self destructive behavior.
Just like how a druggist will face difficulty living without drug, a person who has a habit of watching TV serials will face difficulty while living without it. It basically becomes a addiction.
These are the basic reasons why I don't watch Television, and why you shouldn't too.
If it's already a habit, slowly cut down and eliminate it. If not, at least be conscious of what those TV serials are doing to your brain and your reality. Most of the problem occurs due to unconscious consumption of those TV serials.