Why would anybody want to enable zoom in the first place? Properly designed mobile web apps should already have decent sized text and graphics. In addition to the iOS orientation bug you mention, there's also that annoying click delay.
A lot of people at StackExchange seem to recommend zooming though:
I may want to zoom to see an image up close, or just to change text size. Outside apple, phone screens vary widely, and so do text sizes. You can't hope to find one that works on all phones for everyone.
A lot of people at StackExchange seem to recommend zooming though:
http://ux.stackexchange.com/questions/19464/should-mobile-op...