I find it hard to believe a Spider-man movie could go that low. There is a bottom line to a character like Spider-man, it's not like it could theoretically continue a downward trend forever or it would go negative.
The lower the box office gets, the more hard and unlikely it will be to go lower. There is a bottom end "floor". The bottom end with absolutely no hype may be about 150 million, but it may be extremely improbable to ever go that low unless it litteraly does everything wrong and is absolutely horrible.
Any amount of hype will edge it up above that bottom end. If the next movie gets a fresh rating with the critics, it may very well get about the same as this one.
Also, this movie had the misfortune of being the first Rotten Spider-man. People will likely choose not to go to the theater for that very reason and wait for a rental. For all the people who end up liking the film, that "rotten" stigma will not have as much power in the future. Like for Transformers, every film was rotten, so no one really cares, because the fans enjoy it anyway. If the next movie gets rotten, all the fans who liked this one won't care anymore, so they'll see it anyway.