The choices we make have consequences.

Why is it that there are a significant number of people in born in the
1920s and 1930s who have been interested and involved in mechanical
music?

It began with a much larger number of people who were exposed to
mechanical music early in life.  It wasn't just that mechanical musical
instruments existed, but also that the instruments were found in places
where people felt welcome and had fun.  The instruments played the
music of their times.  Among the masses of people who had this
experience, only a small fraction would go on to become enthusiasts.

People born in the 1940s and '50s were exposed to mechanical music, but
not as an integral part of their era.  By then, mechanical music was
already a bit of history, the nostalgia of the previous generation.
But there was a lot of that, enough that we still have some enthusiasts
from that era who grew up with mechanical music.  The youngest of this
group are over fifty years old today.

Very few people under fifty are actively involved in mechanical music.
What exposure have they had?  Mechanical music wasn't a part of their
youth.  Other forms of entertainment dominated their lives.  It's also
true that the mechanical music community did not cultivate interest
among younger people.  Go to a gathering of antique car enthusiasts --
there will be young people.  Go to a gathering of medieval weaponry
enthusiasts and there will be young people.  Those communities have
succeeded where ours has failed.

Yes, you can say that there are reasons why a convention or concert
wasn't, or shouldn't be, open to the young and shouldn't be planned for
them.  You can make that choice.  Every choice has consequences.  The
child of a serious mechanical music enthusiast should be the best
prospect for the mechanical music community today, but if he has been
excluded as a child, he probably hasn't developed that level of
interest.

What 30-year-old person has had life experiences that would lead him or
her to have a serious interest in mechanical music?  We are witnessing
the consequences of the choices made in decades gone by.  We haven't
cultivated interest among the young.  Neither pet peeves nor any other
excuse changes the outcome.

Meta Brown