It's not that Whedon's a bad writer as such, but I don't think he was suited for Runaways. I don't think the Ascended Fanboy aspect of his appointment as writer helped either, but to me, he just.. Changed up the formula a little too quickly and a little too severely. I know that a big ol' shake-up's what a series needs sometimes, but we went from a relatively grounded team of kids with powers dealing with usually low-level threats in LA to having them flung into New York, dealing with the Kingpin, and having some ridiculous high-concept time travel adventures where Whedon deliberately fucked with the dynamic of the team and tortured one of the characters for a purpose he was never going to explain himself.