I'd probably go down that road too, but I'd also extrapolate from there to create a cosmology and mentality for elementals that makes attacking the summoner an understandable thing to do, which may also imply potential countermeasures and/or exploits. For example, if elementals are ephemeral beings with the illusion of immortality (if, like demons, they are created with a belief that "death" on the Prime Material simply equates to a rebirth on their home plane) and enormous pride in themselves, they may attack the summoner as a punitive measure against hubris and to discourage further summoning. But, a summoner might then be able to get around the concentration limit by releasing the elemental immediately after summoning and flattering it (Panache anyone?) into cooperating with him, with the promise of future favors. Or he might be able to fool it with an illusion, by casting the initial spell in the guise of an enemy (Disguise Self) and then dispelling the illusion once concentration is lost, so the elemental goes seeking his enemy.