I believe that keeping a fulltime job while freelancing as a blogger actually improves content and serves niches better. Here's why.
When you have a fulltime job providing the majority of income, and a nice little hobby like blogging, you as the content creator feel safe financially and write stories that speak to you and your niche. You write with passion, and freedom, knowing that what you write is truly yours with no strings attached. If someone is weirded out by your writing, no worries! The niches you write about love your articles and they keep giving you that little income stream.
However, when you switch to this freelancing gig fulltime, it becomes your main source of income. This can quickly concern you if a post fails to gain as much income as previously. "What did I do wrong?" you quickly ask yourself. Maybe your article was too controversial, or maybe not enough people enjoy your writing. Food and rent depends on your writing so it's back to the drawing board in a quick attempt to gain followers. Overtime, your writing becomes less about YOU, and more about trying to get those sweet sweet views and upvotes.
Hi. I'm Cyborgeek. And I think in the long run, this dilutes content, burns out writers, and bores readers and your writing becomes more and more bland, and the niches that used to love your writing lose interest.
Keep up the positive spirits, and keep writing content that YOU love.