"You do not, in my city, run into bloggers or so-called  citizen journalists at city hall,
  or in the courthouse hallways, or in the bars where police officers gather..."

But this is 2017, and most cities are one-newspaper towns, generally exhibiting close, mutually-protective relationships between commercial media and government decision-makers. I've seen major papers outright lie about events in city council meetings and legislation (for two examples) when they thought nobody would hold them accountable. I've seen written accounts of speakers and audiences at city council meetings that the reporter didn't even attend. (And if you search online, you may well find independent reporting "gadfly" groups or individuals you didn't know existed -- the local commercial media sure wouldn't tell you. Nextdoor can also be useful, but the signal-to-noise ratio is often low.)

One example process: local governments dish out taxpayer money to pseudo-independent "service organizations". Those organizations use part of these funds to buy advertising in local media and on public transit agencies. Those media, in turn, do flowery reporting on those local governments and soft-pedal police violence and union corruption, resulting in situations like "The Riders" in the Oakland Police Department[0]. This is too often the circle of modern urban "journalism". And that's without even addressing the issue of predatory corporate behavior by publishers themselves[1].

The broader point: modern, for-profit media are exactly that -- for-profit businesses. Their fiduciary duty is to maximize shareholder value. Objectivity and honesty are orthogonal to short- and medium-term profit.

[0] https://en.wikipedia.org/wiki/Allen_v._City_of_Oakland

[1] http://www.metroactive.com/papers/metro/05.29.97/spanish-pre...

Read a science blog (almost any one made by an actual academic), and then read a journalist science column. Tell me which one displays "daily full-time commitment by trained men and women who return to the same beats day in and day out". Then go read about tech for example, and see if it's any different.

Indeed, if you ignore economic news, political journalism seems to be better done by biggish professional entities. But they don't seem to have any other niche remaining.

Also, the GP claim about "social media", well, if you listen to it and hear "Facebook", it's certainly wrong. We badly need a better platform. But that does not open the niche to journalists.

> the neighbour with a garden hose and good intentions is not a 'citizen firefighter'. To say so is a heedless insult to trained social workers and firefighters

There's no reason to thing a firefighter would do anything other than their job, there's no obvious reason for a bias.

A uneducated social worker, much like other medical/psychological workers, is a dangerous thing, so many require licences.

What licence requirements are there for professional journalists? I see plenty bad stats/reporting in journalism, so nothing that prevents that.