You got to be kidding. You originally post "I have 20 switches, how do I monitor them?" question" and then bash someone for there suggestion.
Your question should have read, "why does nagios v1.2 only check services, and the host remains in the state (Host assumed to be up). Now that I understand as a valid question, but gees, how do i monitor a host? I would have said RTFM also, but luca beat me to it.
We are all triing to be helpful here, but it's only going to take a few more people to push our buttons, and I will be gone for sure, and luca will probably beat me out the door.
I'd suggest you people adopt an attitude that it isn't easy being a mind reader, so spell out the problem, and don't make us "read between the lines", and surely don't bash us, when we "read between the lines" incorrectly.