Ah, you get your info from google mapsI suggest you use Google maps where you will see that there is a lot of countryside where rocket launchers could be located. Far enough from built up area that returned fire would be very unlikely to cause any civilian casualties.
Gaza City is only a part of the Gaza Strip.
(mind you Israel appears to do so as well)
And fyi the Israeli military HQ (Kirya) is in central Tel-Aviv and surrounded by a hospital, a business district, blocks of flats and a school - so how come they can 'hide themselves' amid civilians and avoid criticism?
Btw - have you ever been to Gaza?