There are "good" banks that have high credit standards and simple businesses - mutual thrifts (they go back to pre-Colonial America in England when communities would band together, pool capital, and one by one write mortgages so that everyone would end up with a home). If you find one that's operated well, they wont be engaging in sub-prime mortgages of extending to credit to those who shouldn't receive it.
The problem with mutual thrifts is that they're constrained by how much they can grow. They are owned by depositors. Usually, when one grows a bit, they're acquired by a larger player who wants a foothold in your geographic area / wants to take advantage of your excess capitalization (let's say Bank of America is capitalized at 4%, I've seen some thrifts at 13%)... you end up having that excess capitalization because of the high loan standards.
The problem with mutual thrifts is that they're constrained by how much they can grow. They are owned by depositors. Usually, when one grows a bit, they're acquired by a larger player who wants a foothold in your geographic area / wants to take advantage of your excess capitalization (let's say Bank of America is capitalized at 4%, I've seen some thrifts at 13%)... you end up having that excess capitalization because of the high loan standards.