I'd have to agree it should be in the core. Members don't want to hear why it won't work--they just want it to work. Hopefully there is a way to do it so that it will work with both GD and ImageMagick (as some do not have access to the latter).
Bumping this thread as its now 2016 and still seeing this issue... Photo uploads from iPhone displaying sideways on Xenforo. Anyone know why this hasn't been resolved all these years later?