We need a national civics course

Why do people think that the First Amendment extends to private business? I ask because of this Newsweek story on Starbucks backing away from selling Bruce Springsteen's new album because of a raunchy lyric. Everything ticks along fine until this paragraph near the end of the article:

Still, it remains to be seen whether the caffeine-beverage giant’s move becomes another stimulant for First Amendment advocates and others con­cerned about free-speech rights. In recent years, Wal-Mart, the world’s largest retailer, has come under frequent criticism for what detractors believe is censorship involving books, CDs, books and other packaged me­dia

Ugh. Businesses do not owe anyone a right to free speech. It may make good business sense, but the First Amendment does not mandate it. The Bill of Rights only applies to government! Get it right, please.