Why don't you worry about yourself? If some parent wants to buy their child an iPhone, that is none of your business.
Ah, but if they spoil the child and the child does not learn the true value of money then they start amassing debt and get loans they have no chance in paying off. Once the economy starts tanking as a result of this gross ignorance of fiscal responsibility, then everyone needs to start worrying about themselves. (Oh crap, I think it's already happening...)
I have no problem with parents buying their kids iPhones. I only have a problem with brats getting spoiled and not learning valuable economic lessons which then screw us all in the end.