Apologizing because he changed his views or apologizing because of the backlash?

Yeah, he did his thing once and he is remembered for that but nobody really cares about most of his opinions anymore.

If we were to believe this piece of the OpenBSD lyrics explanation page isn't satire:

In 1998 when a United Airlines plane was waiting in the queue at Washington Dulles International Airport for take-off to New Orleans (where a Usenix conference was taking place), one man stood up from his seat, demanded that they stop waiting in the queue and be permitted to deplane. Even after orders from the crew and a pilot from the cockpit he refused to sit down. The plane exited the queue and returned to the airport gangway. Security personnel ran onto the plane and removed this man, Richard Stallman, from the plane. After Richard was removed from the plane, everyone else stayed onboard and continued their journey to New Orleans. A few OpenBSD developers were on that same plane, seated very close by, so we have an accurate story of the events.

He's also a pedophile.

The Daily Beast first reported that Stallman wrote in 2003, "I think that everyone age 14 or above ought to take part in sex, though not indiscriminately. (Some people are ready earlier.)" In 2006, he wrote, "I am skeptical of the claim that voluntarily [sic] pedophilia harms children. The arguments that it causes harm seem to be based on cases which aren't voluntary, which are then stretched by parents who are horrified by the idea that their little baby is maturing."

Source