"Do you think the world has room for one more writer?"
Let me tell you what I told him.
As far as your writing goes, you need to pursue your interest no matter what it takes and no matter the outcome. As a writing teacher once told me, "If you're going into writing for fame and fortune, think of a different line of work." She was referring specifically to fiction at the time, but the advice holds firm in many areas.
Where I live, it's difficult for a writer to make a living. Potential clients generally offer fees below the market standard. (One local publication, for instance, pays a small flat fee for feature articles, regardless of length, and has done so for more than 15 years. They've also "soured" the deal by demanding more from writers without any increase in the fee offered.)
If you want to promote yourself as a writer, hit the Internet and find clients throughout the world. Not long ago, Americans generally had deeper pockets when hiring writers (although times have changed).
Try not to write for free unless you're helping out a worthy cause. One of the reasons writing has become devalued is that too many novice writers are willing to give away their work for the glory of seeing their names in print. Online publications are often the worst offenders, although many will pay a modest fee and some pay quite handsomely.
I'm not trying to discourage you by any means. There are many writers out there who make a good living.
There are others who agonize over whether to make the leap from their "day jobs" to full-time freelance work. According to one writer, the final step in her decision-making process was to ask her gainfully employed husband what he thought she should do.
Unfortunately, some of us have no one else to "bring home the bacon" while we get our writing careers off the ground. We hold down full-time, part-time and temporary jobs, deplete our nest eggs and use what little free time is left for writing (that's not even counting family commitments and other freelance work, which vary according to the individual).
In the final analysis, write because you want to write, because you have to write. If you pursue publication, be prepared for rejection but never accept defeat. There will always be room for more writers, especially those with talent and determination -- not necessarily in that order. ;-)