Why blender is not saving used Images I was wondering if someone could explain me why blender is not saving images when I save the project?

I know that this is treated as external data and it's not really big deal to save it manually but consider case where you don't know the program well.
Normally like in all other programs, when you save a project you expect that it's going to look exact the same when you load it again but in blender you could have a Big surprise especially when you spent few hours on it. 
And even if you are experienced user you could forget to save it and little mistake can lead to waste much of your time.

I'm aware of this topic Auto save images along with .blend

But I'm asking why is Blender behaving in such way. It don't seem hard to program such thing so it must be a matter of choice which i can't understand but even a simple warning will be very helpfull.
In order to reduce the size of the .blend file. Blender to a Maximum extent save only relative references. If you want to Shift your project to some other machine.You have to pack all the project files.

To save all the images to the .blend file Checkout File-> External data section