It was not a great aircraft in it's day it was a dog. It may have been reasonably nice to fly for those who had not flown a lot nicer, but it was a maintenance nightmare, always going tech and it caused the financial collapse of more than one airline, Caledonian in it's last reincarnation being one.
For every airline you say the L-1011 caused to collapse there where many more that attribute the TriStar for there success, Cathay Pacific, Delta and LTU to name just three.
Only one airline that operated both the L-1011 and the DC-10 (the TriStar's closest rival) chose to keep the DC-10 over the L-1011.
As far as being a maintenance nightmare? The L-1011's dispatch relibility rate was higher that any other wide first generation widebody. So either maintenance was not that big a problem or the airlines that flew the TriStar were highly skilled.