You are conflating an issue about the older generation and their hypothetical increased resistance to swine flu and using this as a claimed beneficial side effect of an alleged reduced concern over cleanliness in past generations, compared with a generalised overemphasis on cleanliness today.
Of course, the reason why the older generation might have a greater immunity to swine flu has nothing at all to do with a kind of generalised improved immunity as a result of living in a less "antiseptic" environment as you perceive it, and everything to do with the fact that they were around during the 1957 flu epidemic, the active agent of which was very ,very similar to the current H1N1 variant.
I would agree with you on the specific issue that we have had a tendency to oversubscribe antibiotics ( although this culture is changing), and that is potentially dangerous ( witness the spread of MRSA), but I would dispute your assertion that we should be dumping antiseptic sprays, floor cleaners etc.