I don't think this is civic-mindedness at all the great depression taught us that bank runs and failures are contagious. The very purpose of FDIC is to prevent this (and other countries have similar schemes), but it can only go so far.
Putting their own money in can be entirely in their own self interest if it stops problems from spreading. None of those banks want the kind of problems that come with SVB, Signature and First Republic (and whichever one is next).