It means that Linus used to be fairly brusk when he was younger (basis: e.g. flipping people off and telling people to "fuck off"), and recently he has apologized for his behavior (basis: the link you shared). To me this is him mellowing out in his old age. His younger self might not have agreed with this mellowing out, seeing it as unnecessary (basis: his responses previous to the apology to other people who called him out on his behavior). The fact that he apologized means that even he realized that he did not care too much before, but now he does, and therefore he wanted to make up for what he has done.