If thats the case then fights will never end. Youd get characters trolling and reverse summoning when they are about to get killed xd.
Seriously though there are many reasons. For example when sasuke used that manoeuvre, he wouldve been stuck in the snake world, if it wasnt for suigetsu who summoned manda back to where they were.
Secondly it seems if you do not do what is stated above then the summon itself has to summon you to their location. Pa frog always trolls naruto and reverse summonings him to the frog location.
Basically if a ninja decided to do this on their own, they could be forever stuck in the world of their summonings