Yeah, I don't really buy the employee abuse argument either. That just sounds like typical spineless management. They don't have the gonads to directly deal with the ~5% of employees who excessively abuse sick time. They find it easier and less confrontational to just punish everyone.
Fortunately, my current position is really flexible. If I'm feeling ill, I can just work from home so I don't get too behind on my projects. That way I don't get the whole floor sick.