Since they only release once a year, this one doesn't only have to hold its own against the competition right now, but also against whatever the others put out in 10 months.
Yeah, some people will always wait for the next iPhone. But for others, who have a more "neutral" point of view, this iPhone might look very bad in 10 months.
True, but if you look at it like Apple vs Android, the Android camp has many releases a year. So if you're a consumer and you're buying a smartphone in 10 months, your choice is between the "outdated" iPhone or one of the latest Android phones.