Ever see the Mythbusters episode where they lined up toothbrushes to see how far fecal matter traveled. Right near the toilet was the worst but nowhere was safe.
So yes washing hands helps but it's not the be all, end all solution.
I'm sure someone will disagree with me but I think protecting ourselves completely from infection isn't a good idea. Particularly after reading Immune (good but not the best resource) I think washing our hands all the time or using antibacterial soap is not a good choice for our individual health and immune system strength.