Is polling scientific?

No.12307099 ViewReplyOriginalReport
Why do these PhD data statisticians keep getting it wrong? All samples are non-random and the methodology these pollsters use to normalize their samples seems completely pulled out of their asses, for example I often see them cherry-pick axeses where they observed correlations in the past and skew the results accordingly.
Polling seems similar to astrology or technical analysis to me. Should the media stop using polling to make predictions?