The main reason people know his initials is because he was one of the more influential people behind the "Open Source" concept and branding, as a distinct thing from the Free Software movement. He also wrote some fairly well-known books. His fame has declined since then, but his membership in the Three Initials Club has remained intact.

Here endeth the history lesson. Incidentally, you could have googled this if you were interested in hearing an answer rather than signaling indignation and/or contempt.