I also don't tell parents to keep them home when they are feeling ill ~ if that was the case, I'd hardly have any kids in the cold and flu season!
When it comes to teething ~ I agree it can help them feel better and I too am OK with that. However, when you know that your child is fighting a cold and or flu and you know that they should be home and you medicate them and bring them ~ I am so not lax when it comes to that or fevers. A fever is a way of fighting off a virus and or something wrong in the body. To bring a sick one medicated ...you are for sure passing something on.