Your kid is obnoxious.

   I've said this publicly before, but that's not the point. Unless you are very close friend, I probably don't think your kid is cute and find him annoying. I'm going to brag a bit, but my kid is pretty fucking awesome. She's well behaved in public (most days). When she is being a brat, I take her away from public.
  I don't have to deal with screaming, crying, kicking, I'm spoiled rotten and get what ever I want tantrums. It's a combination of being a mom with a back bone and being blessed with a good kid.
  Back to other people's kids. Oh my gracious. I have no patience. NONE. Even when I can tell the kid has been brought up well and the parents are trying, I get annoyed at tantrums. When I hear that annoying, whiney, I'm not hurt cry I cringe.  I can tell the difference between the tantrum cries and the I'm hurt, tired, and/or hungry.

  All that being said, if a little one is being cute, sweet, or says hi I will be more than happy to say hi back. Cause kids can be pretty fun. Mine is just more fun.