why was the witches council against samantha's marriage? why did they dislike mortals so much?

The witches didn't think mortals were good enough for them...and thought Samantha was crazy for wanting to give up her life of magic and ease to become a "normal, mortal housewife".

why was the witches council against samantha's marriage? why did they dislike mortals so much?

They thought Mortals & their way of life to both inferior to theirs and assinine, as well as a threat to their own continued existence.

Just the inter-marriage aspect was a threat as it would have diluted their Witchlieness down to the point that eventually over a very long period of time they would be more Mortal then Witch.

Remember there were very few of them, so much so that when Tabatha was born as the first new Witch of her generation it was a big deal to them as it signified a continuence of who they were as well as an addition to their small numbers, they really were a small minority.

Larry Tate :)