I do see this point, but what about humans that don't currently exist? Like, we cannot communicate with animals, but we do understand what it's like to be affected a decision you had no influence over.
Future children cannot communicate their needs or preferences, but also as humans, we do consider them at times. We, as humans, want to leave some sort of impact, no? We also tend to want to respect the past in some way. So, yes, privately, we feel bad about making the world a worse place for future generations, but that is the full extent of it, just our feelings now. Point is, if we only care about humans, how do we consider others, or humans yet to come, or humans who have passed? We still consider them in our "feelings" and whatnot.