Other people not including the industry making schematic capture software, because it's a fact they can't even agree how to put the symbols in the libraries.
A debate about the desirability of how I'd prefer to consistently do it is completely orthogonal from the fact that the industry as a whole has absolutely no consistency. Not the software and not the users either.
It's most definetely not common practice to make a new symbol for every opamp you use, just so you can simultaneously let the signals flow neatly and have V+/V- top/bottom.