I think this picture is appropriate here:
Everyone has time to exercise. Everyone. Everyone I know who says they "don't have time" to do this or that, has time to go out, time to go on the internet, time to sit and watch their tv shows etc. What they mean is "I can't be bothered" - which is *fine* - it's your body, if you don't want to stay in shape then don't. Just don't expect people to spare your feelings or give you special treatment.