how can people be so rude?

i have observed this quite a number of times and it really irks me to think that most Filipinos are rude.
i am a small town girl and i am a product of a Catholic school. i know my manners. but somehow it's hard to see much older people who hardly show common decency or courtesy. it makes me want to ask where on earth is respect. just because you're older does not mean you cannot respect others.
for instance, not holding the door when someone is behind you or walking quite slowly (because you're texting) along a busy pathway or even simply giving up your seat for old people are quite easy things to do but others can't seem to do it.
in fact i have read in Reader's Digest several years ago when they conducted a study regarding this. Filipinos failed! it's not unbelievable, i tell you. just go to any public place and you'll see what i mean.
earlier today, i was at the supermarket. i was only paying for 2 items so i kindly asked the woman in front of me if i could pay first considering she had about 6 full baskets with her. she rudely said, no and said she was first blah, blah,blah. so i explained that i was only going to pay for 2 items and it wouldn't even take a minute but her husband interruped that he had already placed a basket on the counter, so no! thankfully the i saw a lady in the next counter who was waiting for her turn (with even more baskets than them) and when i asked she allowed me to. it didn't even take me 30 seconds and i was done. i turned back to her and said my thanks.
despite the overwhelming number of rude people, at least there are still a considerate few...