...You think that maybe some people can't do that?
I know tons of kids, whose parents don't support it and won't purchase it for them.
You also have to consider that not everyone has the funds. Anime/Manga is a very expensive hobby.
Lastly, you may not have experienced it yet, but there are times when you will read a manga, and releases will be suspended due to lack of funding, lack of fanbase, or switchng of distributors. Peacemaker Kurogane is an example. I started it late, but it's listed that all manga are released in the states. But no one has four in stock. Upon further investigation, you learn that ADV stopped distrubution at three and didn't release the last volume. Tokyopop picked it up this summer, but will release it with edits and new covers. So that means I have to wait possibly another year and a half for the release of one book, plus re-start the collection because translation/text and cover art won't match up in my collection. The only bonus is that I have rare releases.
You also must understand that some people are too far ahead. I read online and buy. I purchase bleach so that I can own and support it, but I'm also so far ahead of the U.S., that I have to read it online. I do the same for Naruto.
So, stop preaching the importance of purchase if you don't understand some's reasonings. It might be more valid than you assume.