Too often in modern society, we get lazy and use technology as a crutch. I saw a man riding one of those "handicapped" scooters down the sidewalk one day. At one point, the wheels on one side of his scooter went off the edge of the sidewalk, and both the scooter and rider began to tip into the street, directly into oncoming traffic. To my great surprise, the man leaped from his scooter, landed on his quite-capable legs and wrestled the scooter back onto the sidewalk.
I was astonished. "Why would a man who can walk just fine use a scooter obviously intended for physically-challenged people?" I thought. The answer was obvious: because he's lazy. He prefers to let a piece of motorized technology do his walking for him. And if he continues the habit for very long, the muscles in his legs will atrophy, his knees and hips will lose their flexibility, and he'll create the very disability that he's only faking right now. (Granted, I do fully understand that many people truly are physically challenged and need these scooters. My comments here are directed at those who don't need them but use them anyway.)
Much the same is true about the effects of watching television on the human brain. If a smart person watches television for many hours a day, month after month, they will become stupid. Why? Because TV is passive, requiring no exercising of the brain (just like a motor scooter is passive, requiring no exercising of the legs).
The difference is that many people who watch a lot of television still THINK they're smart and well informed because they occasionally tune in to some news program. But even watching the news requires no thinking: the "facts," conclusions and propaganda are all pre-decided for viewers, then spoon fed into their brains through giant television screens.
Smart people get their information through ACTIVE means: reading, primarily. They read books, websites, newspapers and magazines. They may watch TV from time to time, but it doesn't dominate their schedule. Fit people use their own limbs for personal transportation wherever possible, including walking and biking. They may even use certain types of technology -- such as a GPS exercise tracker -- to enhance their fitness training.
So technology, by itself, is not good or bad; it's the way we choose to use it. When we use technology to expand our understanding of the world, or improve our personal health, or to stay informed in a way that keeps our brains active, then technology is good. But when we use technology as a lazy crutch, surrendering our efforts to a machine that does too much of our work for us, technology makes us stupid.
How we choose to use technology is up to us.