I had presumed you meant that the action by targeting one of the airports used most by working class people was wrong, and they should instead be targeting the city boys or something similar... now it just looks like a term that you're using in a way that means you can alter it's meaning to suit your argument at whim.
Let's take this specific protest. I have explained it several times, but I'll do it again if you like.
If activists have a clear understanding of how society works, they can use that to intelligently choose tactics and targets. Basically, the government will protect the interests of the class with the power and the wealth. The corporation generates the wealth of that class. The working class does the work which creates the wealth, but the wealth is channelled upwards to the top.
The corporation is amoral. It is a machine for generating wealth, and it does so with no regard for people or planet. Capital basically wages a war on labour, and unless resisted, its only boundary will be what gets in the way of short-term gain.
So, what do we know about aviation? It is heavily wasteful of scarce resources, it is heavily polluting, and it contributes about 1.6 % of CO2 emissions.
So, frequent flying is obviousy something society is going to have to do something about. Therefore, hitting frequent flyers or business class passengers is the intelligent thing to do.
These campaigners didn't, though. They chose a target proportionately more likely to be working class, and not frequent flyers.
But, you say, the campaigners want to protest about runway expansion. OK, so who is responsible? BAA and Ryanair, for a start. So, target their offices, maybe. An occupation, a blockade.
Not sexy? Done that before? OK, well if you want direct action, then chain yourself to a digger.
They have chosen their target intelligently though. This action was a direct response to the government overturning the local council decision to reject the building of a new runway at Stansted.
But their target was the flyers. It made it look like they were saying they didn't want working class people to fly. Maybe they weren't, but that's what it looked like. Who had responsibility for overturning the council decision? Joe Public and the kids off on a holiday?
If you piss off people who you need to support you, then your action has been counterproductive.