We do our best to communicate the piece to the audience. If they get it, we have accomplished something truly wonderful. I would say this is true of more than just contemporary music. For example, only a fool would claim to completely comprehend the Bach Cello Suites. Any devoted musician spends a lifetime deepening his or her understanding of these wonderful works.
Music continues to change very rapidly.
Music was much different even ten years ago, since composers now have much more freedom. I consider the 60's and 70's to be a very dark time in composition, since composers had to write in a certain style in order to be taken seriously, instead of being given true artistic freedom. But, having as much freedom as we do today creates other difficulties, since, without a little discipline, it's too easy to write music that is meandering and confusing. I think a little structure is important in art, since it helps unify a work into a comprehensible whole. Structure is a very important element in art, something that many don't appreciate.