Personally I never found the bodied ones as despicable as their head-like cousins. They're generally rarer and seem (at least somewhat) more intelligent than the common variety. That and there's a little bit more reflection of humanity in the bodied ones...I don't have a problem with killing some regular yu's but the bodied ones seem like a waste to up and steam like screaming shrimp.
Well, generally human beings feel more sympathy for something the more it looks human-like. The exception, of course, is the uncanny valley where zombies and such fall under.
Thus generally speaking one would probably feel greater sympathy for a bodied yukkuri because it bears a greater semblance to a person that a regular one. Cross this with the fact that most artists and writers like making bodied yus more intelligent and it explains why many people might not mind regular yu abuse but be bothered by most bodied abuse.