Has anyone here written or thought about writing a book or know someone who has written a book?
I wrote a book in high school. A scifi/fantasy novel with dinosaurs. I never published it though, for reasons I'll elaborate in a moment.
Why do people still write books when you can put whatever you want on the internet without the hassle, cost and frustration of finding a publisher?
(A related question is why people still buy books. Feel free to address that.)
First, publishers offer editing and marketing, two valuable services to authors. The deals they make with authors are sometimes quite awful and they're archaic in other ways, but their reason for existing is clear.
As to why I never published that book I wrote, it's in dire need of editing. I tell myself now and then that I'll take the energy to re-write it to fix language problems and plotholes (I cringe a little to re-read it now), but alas I never seem to have the time or creative energy. If I'd had an editor while writing it, it's likely the finished product would be a lot better.
Now I'm not sure what you're asking exactly - why do people still write books as in physical books? or why do they write long form fiction and non-fiction?
I think the answer to the latter is obvious enough, or ought to be. Contrary to a popular idea that all ideas can be expressed in 140 characters or less, long form text gives authors the freedom to explore complex stories, characters, and topics in an engrossing and engaging way. As to the question of physical books, it's simply that dead trees are a convenient medium for presenting and consuming long form text.
Now, this is changing. It's possible to self publish books - Blurb, Lulu, and others offer print on demand for authors, as well as eBook publishing to Kindle and iBooks. I think now the eBook popularity is picking up we may see authors of fanfiction, erotica, and other long tail genres start to take advantage of these platforms. You still miss out on the editing and marketing, but these things have always been a part of the internet culture and even a few sales is money for their efforts that would have been impossible to get before.
I'll also say this about the internet. Part of the reason I never banged out a second novel is that while I still write the same volume of words (about 5,000-10,000 a day), these days they mostly go on forums, message boards, blogging etc. So what you're saying isn't completely invalid - if words per day is zero sum game, then I do indeed write for the internet instead of books.
Do authors think they'll get earn a lot of money? (I don't think many authors do.) Is it the quaint appeal of having something physical with your name on it?
I think most do it because they enjoy it. The human drive to create things and tell stories is a powerful one.
If you were going to write a book, would it be a novel, science fiction, non-fiction, a how-to book, a book of poetry or photography?
I always have ideas for novels rattling around in my head, but I haven't seriously worked on one in years and years - mostly I've been focused on my photography instead. Along those lines I've been thinking of doing a photo book at some point, but at this point it's just an inkling of an idea right now.