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.