Writing is a popular career choice - my local University runs loads of popular writing courses.
Although writing is fun and enjoyable, it can be hard to make a living from writing. Like photography, it's one of those things that people do for a hobby then try to make a living from it.
One good way of making a living is getting a job as a technical writer or technical author. The IT industry is always looking for good writers . On the downside, writing technical documentation isn't as exciting as writing your first novel, so many people find it boring. Software developers and computer programmers usually consider writing documentation to be one of the worst tasks involved with developing software, hence they are usually more than happy to hand over the writing of end user documentation to somebody else!
Technical authors are also in demand in many other industries such as finance, oil and gas and anywhere else where there are procedures to document and operations manuals to write.