Carmack is specifically talking about Scaleform, though! And he's not alone -- I know a few game developers who hate that thing with a passion because it's so slow that it's introduced noticeable performance problems in AAA games.

Because he's clearly talking about ScaleForm/Flash specifically, though, I don't think that his comments can be correctly generalized to all "script interpreters". It's kind of the equivalent of buying a Maylong Android Tablet and going around saying that Android sucks or the tablet market is dead. You just happen to have picked the worst possible representative.