I don't think there is as big of a decline in classical music quality if you consider that these days the real classical music (as in, orchestral music that actually sounds good to the average listener) seem to be composed for film rather than for the opera house: John Williams' opus is incredible, for example.
The unfortunate issue is that these days modern music labeled as "classical" seems to be dominated by unlistenable or nearly unlistenable works composed under the guise of "let's break convention with harmony and so on" thus ending with pieces that might be interesting on an intellectual level but that do not move the average listener at all.
Of course the polite way of putting this is that modern classical music is "challenging", but from my perspective if it doesn't move you (and I don't mean move you towards the nearest exit of the concert hall) it's not really music.
The unfortunate issue is that these days modern music labeled as "classical" seems to be dominated by unlistenable or nearly unlistenable works composed under the guise of "let's break convention with harmony and so on" thus ending with pieces that might be interesting on an intellectual level but that do not move the average listener at all.
Of course the polite way of putting this is that modern classical music is "challenging", but from my perspective if it doesn't move you (and I don't mean move you towards the nearest exit of the concert hall) it's not really music.