While it may be necessary in terms of the storyline, making it a playable scene wasn't necessary. They knew it was going to be very controversial, hence the option to skip. Personally I think that level loses sense of it being a war game and shouldn't have even be considered as a playable scene - especially in a game that is a simulation. Call me soft, but I actually felt sickened just watching it.
Hell, even GTA didn't go so far to make killing groups of bystandars an aim. I, personally, think they went too far. Especially when they know that their consumer base are teenagers, regardless of certificate.