First, I found that there are some true gems in the article and feel it is worth reading. But here is my contribution to discussion through some criticism.

In effect, hacking has arguably grown. Hacker communities,
definitely not. So what went wrong?

I assume an American wrote this and I am wondering if the above is not a mostly US American problem. Of course what is a problem for the US becomes a problem for everyone else eventually in one way or another but at the moment... EU hacker communities are more fluid and inclusive of youth and counter-political cultures. And more often than not the Tenured hackers stick around to work with and collaborate with the new and younger. Though they have plenty of problems I don't think lack of growth is one of them. There are some more inclusive hacker spaces in the US but most of the tenured and serious US hackers went commercial and stayed that way.

In the US context I agree with all the statements. Much also applies to the entire community as a whole. But what is missing is this: the community is just getting old. It is now coming into contact with what happens to any new field of discovery or thought: tenure and structure. It's a problem with memory in general. As it is created there becomes an assumption that one should reference it. This field has history now and those that come along will be forced to consider it just as someone who studies photography has to think about Atget. This requirement adds latency that naturally changes the makeup of the field.

It is important to note that our capitalist worries are
more deeply rooted in us than might seem at first, even
in the most politically diverse people. Supporting oneself
is not easy, it does not come for free. Getting some
education, finding a job, staying up-to-date... regardless
of what your aspirations are, whatever you feel obliged to
do is probably a lot, already. And it likely involves a
prevalence of "minding your own business".

Much of the article has to do with productivity issues. This is not unique to our field except that once upon a time the median age of the field was a teenager with lots of energy and time and now median age is older. It is true that the grind of day to day in societies like the US that hold capitalism as God makes it harder for one to have time for much else than survival. But 1. this isn't the case everywhere yet. Just see some of the newer capitalistic societies in the EU that have not yet shed every part of socialist history just yet. (ahem, Berlin!). 2. One should also consider that we are just getting old. Want to solve these problems, be less freaking proud, more inclusive and bring in youth. It's the same for every field. The article perhaps says the same thing but better:

If our thoughts on creating hacker groups were to be
summarised, this is how they would look: No one ever
feels like we do. They are not to be trusted and we do
not have the time for them. The only attitude consonant
to our search for a comfortable, safe life is to constrain
ourselves to our own limitations, ignore the intelligent
life out there, and surrender to the mediocracy that our
society has condemned our leisure time to.

Side note: these problems might relate to the fields chauvinism problem. from my experience women are twice as likely to be inclusive in this field. there could be many reasons for this but it's worth considering that the inclusive problem and lack of trust actually may be related to the male chauvinism issue.

Finally, that Anonymous and these types of communities will not have as much impact as l0pht, mod, lod, others... is seriously debatable!

This article discusses why recently we do not see many
hacker groups anymore, and why the ones we do, such as
Anonymous and its satellite efforts, do not succeed in
having the same cultural impact as their forefathers.

Most of the older groups such as l0pht spent their time saying XYZ company sucks because their developers missed a bug in a product. Whereas anonymous spends its time saying XYZ Gov/Inc/Policy sucks and we should riot. Which one do you think should have more impact?