Documented cause
Disney acquired Lucasfilm for $4.05B in October 2012, gaining LucasArts in the process. Despite LucasArts having ~150 employees and Star Wars 1313 in active development, Disney shut it down in April 2013. Disney's reasoning: licensing Star Wars games to EA (a deal signed days later) was more profitable than running an internal studio. Star Wars 1313 was cancelled; the LucasArts legacy of adventure and action games ended after 31 years.
Alternative account: LucasArts was founded by George Lucas in 1982 as the games division of Lucasfilm. It produced some of the most celebrated games in history — the Monkey Island series, Day of the Tentacle, Full Throttle, Grim Fandango, X-Wing, TIE Fighter, and the Jedi Knight series. By the 2000s, LucasArts struggled to keep pace with AAA development costs and shifted almost entirely to Star Wars tie-in games with declining quality. When Disney acquired Lucasfilm for $4.05B in October 2012, it inherited LucasArts. Disney assessed the studio, concluded that licensing game development to third parties (EA) was more profitable than operating an internal studio, and shut LucasArts down in April 2013 — eliminating ~150 jobs and cancelling 10 active Star Wars game projects, including the much-anticipated Star Wars 1313.