That's debatable. If something naughty is being represented, it doesn't matter how poorly it's being represented.
Besides, he might have installed a graphics pack for all we know.
Anyways, chunks are a little tricky. The [NO_BLEED] tag will stop critters from bleeding, but it won't stop chunks from appearing. Also, bleeding is an important part of the game, seeing as it's the only way certain injuries can be fully expressed (if you can't bleed, getting your heart pierced doesn't do a whole lot).
I think it's rather silly, but if you feel "blood" is just a little too close to home, there are alternatives. It is possible to get a creature to bleed the mysterious white "ichor", a dark grey "goo", or even a verdant "slime". I think it's even possible to get magenta blood.
Those are the slightly less disgusting alternatives. Being Dwarf Fortress, it is also possible to get a creature to bleed vomit. Or pus.
These are all just bloodtype tags. [BLOODTYPE:W] will give you white ichor, [BLOODTYPE:0] will give you blackish goo. The others are "M" for magenta, "G" for green, "B" for blue, "C" for cyan (it's more of a teal, really), and "Y" for pus. "VOMIT" and "SLIME" values are self-explanatory.
There is probably some way to keep critters from losing their component parts, but I don't know what that would be.