The author of those words in Matt 13 is reusing the metaphor from Isaiah 6 to supplement his source document (Mark).
There the prophet blamed the people for not agreeing with him. The fault was theirs not his or his arguments. Similarly 700+- years later the Matthean author felt that Jews that did not agree with him were somehow deficient, the fault was theirs.
Ironically Isaiah would probably have been one of those for just two verses earlier (7) he declared his sins were atoned for and guilt removed.