I believe that such attitude can be brought about either because the child was borne "hereditarily" hard-headed or the parents are good at spoiling them.
Whichever way, seeing a child throw tantrums brings about negative reactions form observers. It is irritating to hear them wail loudly with pretentious tears (or sometimes none showing even), or see them sulk kicking or throwing away everything they see, or even lay on the ground screaming and thrashing. Most of the time the people disapprove of the childs behavior and condemn them for it, but on my end, I pity them because they are not being guided accordingly, nor are they being trained as should be thus will be the one suffering or will suffer when they grow older. Because with such molding they will surely be formed imperfectly and be the one to be hated or avoided. Furthermore, I put the blame not on the kids, but to the parents who seem to lack proper education themselves or enough knowledge to foresee the after effect of this in the childs latter years....or possibly loves their children less for not caring enough to put them to right. IT IS THE PARENTS RESPONSIBILITY TO GUIDE THEIR CHILDREN.
Unfortunate to see that when the kid has already built his foundation, used to such way of behaving (of having his way all the time), then and only then will the parent try to straighten them out with punishments. Is that fair? And so, shape them while they are still moldable and not when they are already stuck to that shape.
People differs...and so parents differ as well. Being one now myself, I then can look back and thank my parents for loving me enough to have this knowledge that I can now passed on to my daughter, their grandchild.