User blog comment:Morgana High Priestess/Which reign is better: Uther's or Arthur's?/@comment-3012002-20130120111653/@comment-5674726-20130120115943

''Uther said "Oh, Merlin's dying, he can't be saved, he can be replaced" but Arthur defied his father saved him. See my point?''

What if Arthur had died while searching for the cure?

Camelot loses its heir and its military leader. Even if Uther named Morgana his heir, she wouldn't be able to take over Arthur's military role and the kingdom would be weakened. Uther was thinking of his son's life and of the good of the kingdom as a whole and, from where he was standing, it would have been idiotic to risk Arthur's life for the sake of a servant. It's not as if he was aware that Merlin was going to spend the next decade using magic to come to Arthur's rescue on a regular basis.

He didn't consider Merlin's life "worthless", his position was that it was "worth less" than Arthur's, a position that Merlin himself espoused when he offered his life in exchange for Arthur's.

I'd say that Uther's mistake in that episode was that, when Merlin accused Lord Bayard of poisoning Arthur, he essentially put him in a lose-lose situation; if the cup was poisoned, he'd die but if it wasn't, he'd be left to Bayard's mercy and would probably be killed. After that, you couldn't blame a servant for not wanting to speak up if they thought that a member of the royal family was going to be poisoned.