Of course, it has always been difficult for unknown writers to gain a forum.  But today, there are structural limitations of a kind that previous generations didn't experience.

From the invention of the printing press until somewhat later than the introduction of radio, what entered into general public discourse was basically a matter of seat-of-the-pants impressions on the part of individual human beings.  "That's good!" or "That'll get them yapping!" or "This will sell some copies." an editor or publisher might say.

Today, market research seems to have all but replaced such subjective judgments.

There's barely a little journal or FM radio station out there that hasn't bought exhaustive statistical analyses of not only how many readers or listeners or viewers it reaches, but also what their ages, incomes, and educational levels are, perhaps what overall lifestyle and attitudinal "clusters " they fit into, plus how they typically use the information, and ultimately, whatever can be quantified (all other things being equal) about what they find "interesting."

The practice of such refined statistical analysis requires hard, objectively quantifiable data--definable categories of subject matter, for example, rather than subjective attributes like "fresh perspective" or "wit" or "colorful writing."  

The result has been an increase in narrowly-defined niche media, such as the magazines Runner's World and Working Mother, and a decline in general-interest approaches that require someone to make a subjective decision about what an educated layman would find noteworthy.

What complicates the picture is that, beneath the surface sophistication of the sampling techniques and statistical modeling and projection, nobody actually has much of a handle on which particular article or item people read or paid attention to in a newspaper, magazine, or newscast. 

Reaction to recurring items, like the commentary of a regular columnist, can be sampled and calculated, but interest in one-time articles is simply more than anybody can pay to measure.)

The result is that even if a particular piece causes sales or viewership to go sharply up or down, nobody's likely to have more than a vague hunch about it.  

Less still is known about material that people don't rush out in droves specifically to buy, but which significant numbers of people may find appealing, worthwhile, and a good reason to watch for the next edition.