I was bored, so I did.
Within a few months, I had founded a magazine. My co-founder and I bootstrapped it, so we didn't have access to the highest caliber of writers. Consequently, we did a whole lot of development work; taking writers with passion and some technical flaws and working with them until they could bang out some good quality content.
I learned something really valuable working with young writers. The 'write for you' advice is great...to a point. If you really want to become a good writer, you need to write for an editor. Find someone you trust and get him/her to butcher your writing. Write for that person.
The problem with writing for yourself is that it is too easy to say, "well, the audience didn't come because x." (where x != my writing sucks)
The joy of writing for a good editor is that you will improve faster than you can possibly imagine. And then, you can say, "who cares about an audience, I'm a better writer now."
You can become a great writer...anyone can. Hell, if you can write code, you're already 95% of the way there. My email address is on my profile - if you want someone to edit your stuff, send me some mail...