Writers can, at least on occasion, find themselves with nothing to write and up against deadline. I once wrote a monthly column for a writing magazine. In my five years as a columnist, there were times when I had no ideas in my drawer and would have to scramble at the last second. It happens, and the "content hole" must be filled by words (if not ideas, alas). I can't imagine how newspaper columnists who produce something twice a week can consistently generate ideas. They must be the ink-stained wretches Dr. Samuel Johnson once talked about -- though few writers are exposed to ink anymore (how about "laptop-toting wretches"?).
Many of these columnists seem to read each other, and so the columns become a kind of echo chamber. When one of them, for examples, writes about presidential candidate Bernie Sanders and his appeal among millennial voters, you can be sure than fives will join the fray writing about Bernie and the kids. It's not just imitation (often the sincerest form of flattery) but the impossibility of coming up with great new ideas all the time.
Every writer confronts an "ideation gap" at some time. Ideation is this writer's fancy word for coming up with ideas. If you're lucky and good, editors may approach you with ideas -- or maybe a client will. This saves the "ideationally-challenged" writer from having to sit down and try to think up something (hey, why don't millennials love Hillary Clinton, for example?). The writer can always remain fallow, allowing the exhausted soil of his mind to regain nutrients, but doing nothing is hard when readers and editors want something to read.
What if you can't think of any ideas, but you need to write something fast? In my view, you're not ready to write until you have the urge to say something. It would be better if you said something that is either (1) important to you or (2) important to the reader. Combining (1) and (2) would be best, of course. Passion and purpose drive all good writing.
As a writer sans ideas, you can always start out on a verbal journey and hope the reader keeps following you along. If you're interesting and honest, and have a voice, the reader might come along for a while, but it's always a risk to lack ideas and have no clear destination.
Even this post, which may seem disjointed and "ideationally-lacking," is actually about something: the idea of not having ideas. I think that I'll ask my curious co-worker what he'd like to read about, or ask my supremely-patient readers for idea suggestions (use the comment box below, and thanks for reading). I'll do some of my own thinking too. Who knows, I may even come up with something.