This may not be one of the best shows of all time, but at the same time, I really can't see why anyone could say this is a bad program. Maybe it's because the show hasn't aged as well as some people might have hoped.
The mixture of the scripts - sci-fi, horror and fantasy - is great. Although the original "Twilight Zone" (which I believe aired around the same time - and which many people have compared to this series) is better, this show remains to still be a great golden oldie. Still very much recommended to fans of this genre.