Every generation believes that the next generation is less intelligent. It's part of human nature. I doubt common sense has ever been as common as most of us once believed it to be. The more connected the world becomes the greater our exposure to the idiocy among us also increases.
Until recently when the average person said something stupid it was likely to be forgotten. 1 or 2 friends/relatives might bring it up at the next Christmas party for a good laugh, but it wasn't a big deal. Now with social media+cell phone cameras the average person can broadcast themselves to the world at will.
There may be a slight rise in idiocy due to the attention it can now bring, but I'm sure evolution will eventually catch up to technology, and civilization.