Why do you think Uther hates magic so much? Is it because he fears it?

In a nutshell, he made a deal for an heir. Ygraine, Arthur's mummy,paid for it and now, his guilt forces him into the luxurious corner of casting blame on everything but...himself and his choices. EVERYONE MUST Pay for his guilt. The irony is, he is surrounded by magic in all its forms...he is a flatulent ass and my favourite hate.

I think he fears it and needs to control it. I also think that he blames it for loosing Igraine. Or more like it is his scapegoat. He feels guilty for using magic that took the life of his wife. It is easier to blame the magic.

He fears it will make people evil and sometimes is used for good. And magic is strong it even can defeat uther that why he hates magic so much

I think he could not or would not be blamed for Ygrines death.
and I think he must have something and blame to go further.

maybe because his wife died because of magic for his son to be born and he really wanted a son

Its not guilt. It’s because uther understands magic can never do good in this world. And it is useful to hurt people who don’t know magic. Either everyone must know magic or no one. He likes science.