I know I'm a late, but there are several Fighting games with better plots then Mortal Kombat. Blazblue for example. Well I feel that Blazblue has a better plot.
Mortal Kombat and Tekken are the only stories from fighting games I enjoy watching. Granted, not very many memorable ones outside of those two but it's so strange I cannot bring myself to even half-heartedly entertain myself with the questions of what happened in various other titles.