That doesn't make any logical sense. All that suggests is that you have n=1 experience with people over the age of forty.
As for observing that agile events in your neck of the woods are full of older people, there are many, many possible explanations for this and your blog post advances one without providing evidence that it is anything other than confirmation bias.
One thing I would do before making a statement like that is attend some other methodology events and check out the ages. If you go to a CMM conference, how old are the people? How about a PMP Institute gathering?
You may find that older people are more interested in methodologies while younger people are more interested in technologies. You might not, but your essay does nothing to establish that your explanation carries more weight than my conjecture.
And if my conjecture is correct, your point really should be that "Excessive interest in methodologies has the smell of death." That might be true!
I am not saying you're wrong, only that your essay is not persuasive on this one point.
CMM and PMP are basically anti-agile. They are useful, but useful for projects that just shouldn't be agile. The fact that agile events attract a similar demographic isn't a positive, in my opinion.
Compared to what, exactly? What development management practices do have an "us" demographic for younger people? One possibility is that you will reply and name one or more named practices with a "young" demographic, and I will accept your point.
The other possibility is that there really isn't a development management practice that has a "young" demographic, that young developers just aren't into spending a lot of time thinking about practices.
If the second case is true, I really believe it undermines your point. If young developers don't really align towards any particular named repeatable practice, Agile is no better and no worse than anything else on account of the age of the people interested in it enough to attend events. It isn't worth "hating" agile for its lack of traction any more than hating PERT charts or Theory of Constraints.
That kind of stuff is pretty boring for the younger generations who are still caught up in the idea that shiny technologies and gargantuan coding sessions can save the world and make them all billionares.
You find mostly older devs at meetups about process and methodology not because it's and old and boring subject. Rather, because they're the ones who are concerned about process and methodology and are more likely to be at a management level.