Do you want to go back to the 2mp camera in the 1st iPhone?
To say Megapixels don't matter is ludicrous; however they aren't the only measure of a great camera.
For the past FOUR phones Apple hasn't up'd the megapixels and their logic was sound for most of it as they made other improvements. However, as technology gets better the same quality of photos can be taken at higher megapixels, which is an improvement for sharpness and cropping which many people want. It's time to increase the count.
Side note: Apple has also held this back since they still sell 16gb phones to most people. And Apple users clearly take lots of pics, and the 16gb phones fill up quickly enough as it is because of photos. Increasing megapixels will likely force Apple to start the phone at 32gb, something they have been clearly avoiding for years at this point. Also the thinness of the phones is another reason.
Considering Apple's camera actually beats the other cameras with twice the MP, your comments are funny.
If you collect 16MP of garbage (because of noises or limits in the lenses), are you actually getting a better picture : not at all.
Thickness of the phone versus the size of the sensor and the quality of the lense all limit the practical resolution you can get. Are you telling me you want a thicker phone just to get a better camera? Disregarding all the other reasons for wanting a thinner phone. If that's the case, well they probably won't be able to serve your particular needs.
Also, 16MP of the same scene at the same JPG setting with a sensor of the same sensitivity (and same amount of noise) and similar lense won't give a much bigger jpg file unless there is much added details revealed in the scene itself as resolved by the lense in the current lighting.
Considering the optics of existing phones, your not getting much added details at all, thus the file if it gets bigger with more MP, it would be from resolving the noise coming from the sensor itself! Often, post-processing just smooths these pixels out and your left with a 8MP sensor file the same size as the 16MP sensor file. Why? Same amount of detail.
The key is getting a good picture, not having the most pixels. If you are able to get both higher MP and the best overall photo, that's fine. But, one should not be compromised for the other.