Compact cameras and interchangable lenses

May be a stupid question but can someon clarify to me why compact cameras don't have interchangable lenses ? it' s a tecnical issue or simply because we want them pocketable ?I have a panasonic lx 5  ( which for me is not pocketable) , a very nice camera but often i feel limited by the short zoom, so would be nice to have the opportunity to choose a different lens sometime. I don't like micro 4/3  because lenses are slow and too big for me when compared which the lenses we found in compact cameras.

Thank you in advance