Soundwave is an extremely impassive unemotional Decepticon (whether he's got no emotions or is just cold varies with the continuity). But he must care for something, right? So what exactly does he care for? - Megatron (his boss, who obviously looks out for him and to whom he has loyalty - unless he's too weak to risk supporting, which is why Soundwave said nothing in TFTM. He did return to Galvatron's side afterwards...) - his minions (Ravage, Laserbeak, Rumble, Frenzy, Ratbat - they're the closest he has to family) - in CYBERTRON he cared for his partner Sideways and their homeworld Planet X, but that's more an alternate universe really... ... and that's it, I guess. That's all he's ever really cared for, hasn't it? A strong leader to keep behind and his own soldiers to lead.