Lockheed is still in business. They did however, get out of the commercial market. The reason L-1011 production stopped is because Lockheed lost market share to McDonnell Douglas with the DC-10, Boeing with the 767 and Airbus with the A300.
Because of the high loss of life and media coverage orders for this new plane dried up over night, airlines already flying them sold them off and the company building them eventually went under.
Baloney. The Eastern crash in the Everglades occurred in December of 1972, nearly 11 years prior to the cessation of production in October of 1983. 229 aircraft were delivered post crash. Even though they built 252 Tristars they never recouped their development costs, loosing $2.5 billion on the project. Competition is what killed the L-1011.
The L1011's were still used but mostly in the air freight market.