I tend to agree with the idea of sticking around. After all, for the most part, you are already familiar with the area, know where certain supplies can be found (yours and other's) and would have the convenience of all the supplies/tools/weapons that you might not be able to take with you in a bug out scenario.
I also think it would be easier to defend a known area, your home and immediate vacinity, than to risk the "getaway" route(s) that will be used by so many unprepared individuals. The risks would appear to be greater if you were to leave, not only in personal danger, but the idea of blocked roads and unusable escape routes.
Help others? Yes, I feel I would, but there are also those that I might not. There is safety in numbers.

However, there are a number of things that could change ones mind. I know if 1/4 (1/10th?) of the population of the LA basin decided to bug out at the same time, "road anarchy" would prevail. Road rage would take on a new level of inhumanity; I can only imagine the number of weapons that would be carried in a bug out scenario and not necessarily in the hands of the best trained or most stable individuals.

Depending on your location and the size of the local population, defending your own turff sounds like it would make more sense.