The funny thing is, Uther isn´t even really the antagonist.
Sure he is a threat, and would kill Merlin for his magic. But so far each episode had it´s own minor antagonist. And usually it´s people that use magic. With Nimueh being a bigger deal since she has been in multiple episodes and hasn´t died yet, unlike every other villain we met. So Uther has some point about magic being used for evil. But he still sucks and doesn´t differentiate at all.
I think because it´s season 1 and very early on they are just trying everything in terms of relationships. Arthur and Morgana felt like something could be there a few episodes ago, but I guess it would be weird, since they basically grew up with each other as siblings. And Gwen is into every guy she meets. Just last episode she kissed Merlin, and now she has a thing for Lancelot. And based on the legends she should eventually fall for Arthur. So yeah, I think they are just trying things out and see what works and what does not.
It was fun to see Lancelot, even if he isn´t sticking around because of Uther.
Also it´s nice that someone else besides Gaius knows about Merlin´s secret.