As it happened, the reaction to web apps was so negative they ended up releasing their SDK hastily (which anyone who went through the pain of using it for the first couple of years can attest to).
One of the common mistakes people have when discussing Steve Jobs is mistaking what he said for what he believed. (We see this confusion constantly in the news, where "The Whitehouse believes" is used to describe something in a press release.) He knew how to stay on message, and he knew that saying "our SDK will probably be released in alpha form in a year and be somewhat stable in two years" was off message.
It's also fairly clear that if he had had a bunch of arguments about something and reached some provisional conclusion, he wasn't going to have much patience with an argument he had previously encountered and beaten to death from someone random.