Parking wardens, speed-radar police and building inspectors make easy targets for anyone wanting to have a go.
But the credentials of those weighing in on the Ministry of Business, Innovation and Employment over its change to fire rules this week mean their brickbats deserve careful examination.
The Society of Fire Protection Engineers, the Architects Institute and the Property Council don't always sing from the same songsheet.
But on this they're agreed that the ministry's Building System Performance branch has got it and the timing badly wrong.
A whole clutch of major building types, including big shopping malls, warehouses with hazardous goods, and likely large multi-residentials can no longer be designed under a certain set of fairly black-and-white rules.
Instead, different, less defined rules will apply, with different oversight, and more of it from councils and the Fire and Emergency agency.
This, say the engineers, architects and developers, is exactly what the ministry said it would not do during a mid-year consultation in case it shocked the industry.
That, says the ministry, is because the consultation reached no consensus - and as for a promised five-month transition period, that's not necessary as the changes "merely clarify" the fire rules.
That clarification, however, extends now to warnings the change might well cost some big projects dearly in time and money.
Waikato fire engineer Debbie Scott told RNZ she had between five and 10 clients whose unconsented fire designs she will have to look at all over again.
"For those buildings currently in the advanced stage of design ...this could require the fire engineering to be redone," said the Property Council, which will hear the concerns of shopping mall developers next week.
"For less advanced designs, the fire engineering required could be more than originally planned and costed."
The ministry has apologised for the process. But it maintains the change itself is to put "public safety first".
Predictably, that provoked fire engineers who see their daily task as striving for just that.
Reading between the lines, the ministry's suggestion that Auckland Council had been seeing some unsafe fire design going on, raised the temperature further.
The council's part in the fire rules change is unclear, but just last year it cited safety fears when it managed to strong-arm the ministry into fast-tracking stiffer regulations around glass balustrades.
At the ministry, it's a worrying start for the new-look Building System Performance branch.
Its first-ever restructure only kicked in on 2 October - six years since the Christchurch earthquake, and five years since the super-ministry was formed, during which time the building branch was rated the worst-performing of any of the ministry's seven regulatory arms.
Not the best look in the midst of a building boom.
It is a repeated refrain among the more sceptical construction professionals, that the building branch's overhaul means it is shedding technical expertise and veteran industry knowledge, and replacing it with policy people - "wonks", the critics say, who can't tell the difference between a "clarification" and an impact.
The fire rules confusion has added some real weight to those brickbats.