i mean, what kind of people write PLR articles, a saint or what? cause i think they are so nice by giving away the articles with PLR. what do you think? or you are one of the "saint" ?
Well, not all PLR articles are given out for free. There are PLR article packs out there that are for sale.
When given free, it's a common strategy toward gaining exposure or keep sales of PLR article packs coming afterward, as What already noted.
PLR stand for Private Label Rights which mean you can do anything with the articles. But it still depend to what is stated on the PLR license though.