Sure he's gruff and kind of grouchy, but remember - he's got a teenage son with extraordinary powers none of them really understand. To say nothing of the fact that he's got everyone in Smallville trying to find out what those powers are and where he came from, and how they can exploit Clark for their own means. Top it all off with the fact that Clark doesn't really see yet (he will, in time) what the Luthors are really about and you can understand why Jonathan isn't the happiest camper!
Besides, the Luthors keep throwing the Kent's for a loop, so no one quite knows what to think of them (even though we know that later on Lex turns evil). Lionel seems like a pretty obvious case of bad-guy, but even he can confuse us, as in last week's show when we saw he had a file on Clark (bad), yet blew away the villian trying to harm Clark and Martha (good). But when we saw in flashbacks how Lionel tried to blackmail the Kents back when Clark was a baby, you can understand why Jonathan doesn't like him. And as for Lex, I think Jonathan has his suspicions that the apple might not fall far from the tree, but right now he just looks like he's being some over-bearing jerk for not wanting Clark to be friends with him. And again, as we the audience knows, Jonathan will turn out to be right in the end.



