calling concrete "cement" is just wrong, there is no debate. The only reason you would call it that is that's what some old dumbass called it who learned it from some other even older dumbass and then passed it on to you.
And then also they pronounce it SEE-ment just to sprinkle a little layer of gross on top of being wrong
This exact discussion was recently had on the Phog in the David Booth Erection Thread.
And I must confess, I too will take one spit into the urinal or terlit, and I too have no idea why. Just an ideal spitting opportunity?