I'll consider classical to mean "Western Concert Music" and not exclusively 1740-1820ish, but the answer is the same for the so called Classical period: Yes, certainly.

Some examples:

In the early 17th century Giovanni Artusi was complaining about Claudio Monteverdi's music, calling it crude and full of instances in which proper compositional technique is ignored.

Beethoven is a famous example, presumably telling people things like "don't worry, this is music for the future" when questioned about wtf he was thinking writing that kind of thing. There were comments about his music being too difficult, too dissonant, having no order...

Liszt and several others started a movement promoting innovations in music, saying things like "new wine needs new bottles," trying to get away from the stiff structures of yore (which Brahms and friends considered as a pretty solid way to compose, without silly experiments).

The whole 20th century was kind of a race to see who was the most progressive. There almost was a riot at the première of Stravinsky's Le Sacre du printemps, in 1913 (some people were not really OK with that kind of music)... Experimental music was considered WAY OUT THERE by a lot of people (some times it still is), and we have examples like La Monte Young's Piano Piece for David Tudor ＃1 in which the pianist is expected to "bring a bale of hay and a bucket of water onto the stage for the piano to eat and drink. The performer may then feed the piano or leave it to eat by itself. If the former, the piece is over after the piano has been fed. If the latter, it is over after the piano eats or decides not to." There was also John Cage, at it again with cacti.