It's called environmental immunity. Those kids will end up being healthier than the ones that wash their hands every time they touch something.
Environmental immunity literally just means the immune system characteristics that you get from your environment. From what I've gathered there isn't anything substantial actually saying its "better" or that you'll be healthier, its just saying that most of your immune systems "information" came from being exposed to things in your environment. While it seems plausible that it should boost your immune system (there is some evidence that kids growing up on farms do better for instance), it doesn't always work that way.
It'd be better to figure out a way to offer common vaccine like exposure to a broad spectrum somewhat regularly.
Plus, environmental immunity doesn't really matter with stuff like MRSA and the nasty bugs that you actually need to worry about. Likewise, it wasn't environmental immunity that handled stuff like Polio, and its not going to handle stuff like Malaria, Ebola, HIV. I don't think it will even matter with regards to colds or the flu either, as those generally mutate fast enough that unless you got lucky and had a decent immune response triggered fairly recently, its not going to help you much. But simple sanitation measures has shown to have helped profoundly in reducing exposure to a lot of diseases (take various forms of the plague, which are still devastating when they hit us, but by limiting our exposure to it, we've made it almost a non-factor).
Hell look at Africa (and other similar regions of the world where access to clean drinking water, let alone enough clean water to just simply wash your hands regularly, is scarce enough and a major reason why they're at risk of serious disease outbreaks). If environmental immunity was so damn important they wouldn't be getting ravaged by a multitude of diseases (or would have evolved into superhuman beings). I suppose you could argue that with our more limited spectrum of serious disease that more developed places would be the prime place for environmental immunity.
Oh, and I think the point the OP is making is that there are lots of people that specifically need to limit their immune system exposure (and exposure to allergens), and by making it easier for everyone to have access to simple sanitation measure will benefit those kids.
I highly doubt that washing your hands a few times a day will limit the average kids exposure to those things that provide environmental immunity (there's a good chance a lot of the "healthy bacteria" they won't be exposed to at all anyway unless they're in the right environment where those germs are thriving but others are not, a big reason why you're not likely to be any healthier by washing less in typical modern environments). But it could greatly help kids that are at higher risk. Hell it could very well actually provide those kids more environmental immunity by lessening the overall load of things they're exposed to as well as should reduce the overall amount of those in the population (meaning likely weaker strains that immune systems can more readily handle). Much like how even though the flu vaccine has generally pretty limited success (some years better than others), its still important enough to be worthwhile.
Actually, what does the data even say with regards to the flu and significant but not serious illnesses? Are they even rising? I'd guess that they're down significantly from even 50 years ago, and likely just ebb and flow a bit depending on various factors (i.e. population mixing, strains). But look at how an outbreak of just a few people is treated as a major issue now.
That's not to say that its not possible to go overboard. For instance, overexposure to certain cleaning chemicals could very likely make you less healthy. They're finding out that antibacterial sprays in particular are worse (likely because of being inhaled, and causing inflammation of the sinuses and lungs). I know a lot of people that spray Lysol in the air (even though its a surface cleaner).
But then, we really can't say a whole lot for certain, and we're still finding out a lot of things (I think its been shown that you're not too likely to get sick via your mouth, its more your eyes and nose, so keep your hands away from your eyes). There's some belief that we've already killed off a lot of the beneficial bacteria, so even if you stopped washing as much you're just not likely to even be exposed to the good bacteria at this point, but will increase your risk of contracting harmful stuff.
I don't think he said it had to be antibacterial soaps. And that's as much because they were shown to be causing actual harm as well as not being any more effective than normal soap. Kinda like how companies are supposed to stop putting those little plastic beads in soaps, since they provide no real benefit for cleanliness, but do provide harm in the waterways.
Yep raise the kids in a sterile bubble then when they get exposed to anything it eats them up alive.
Except that's not true. They're still getting exposed to plenty of diseases. But we also have substantial populations of people that are at serious risk.
