Usually people say to me that classical music is boring and/or too long.
More often they comment on liking one or two of a very few pieces that
are loud and relatively simple such as the 1812 Overture.  They are also
usually relatively short.

I suspect that people dislike classical music--or prefer other music--at
least partly for two reasons.  It is more challenging to listen to than
other music, and some of the developments that have occured in the 20th
century have seemed very strange and off putting to many people.

Music, like language, has to make sense in some fashion.  Also, like
language, some music is harder to understand than others.  It is relatively
easy to sit and listen to a singer sing along with music that is largely
repetitive and structurally relatively simple.  Much of the meaning will
be contained in the words that come out of the singer's mouth.  And,
although one can certainly listen to the instrumental portion of a pop
song and enjoy it, it would become very boring after a while and I think
that it would sound somehow incomplete.  Classical music is often purely
instrumental or frequently the singing is done in a language other than
one's own.  It has rules and structure but they are not bound together
through repition to the degree of other forms.  I think that this makes
the meaning in classical music something that is more abstract and harder
to follow than in most pop. It's the difference between watching
television and reading a book, but perhaps more extreme and most people
want to relax by doing something that is easy, not something that
challenges them.  Also, it is entirely possible for one to get introduced
and turned off to classical music because of this aspect of it.  If
someone's first ever classical performance were a performance of something
by Stravinsky, for example, then it seems likely to be rather off putting.
I think that Stravinsky is a much more challenging listen than something
like Tchaikowsky's 1812 overture.

A few months ago I heard a live performance of David Ott's concerto for
two cellos.  It was a very modern composition and one could easily have
told that it had been composed in the latter half of the 20th century
without knowing who David Ott is or anything of the sort.  It had much
to offer and much merit to it, but after a while it simply became too much
to listen.  During the intermission that came right after the concerto, I
asked the person I was with for an opinion of it.  The reply I got was that
it was just "too too" which summed it up rather well.  It was a challenging
piece to listen to but it was too dissonant, too staccato and too much of
other things to be something that most people would want to listen to for
pleasure.  I think that a lot of modern classical music has gone too far in
the directions of dissonance or other features for the majority of people.
While I would not say that it is bad music, much modern classical music is
clearly "too too".  I think that may have had the effect of driving some
people away from the genre.

Female Schatz