One of the biggest mistakes you can make in life is to trust a person who will betray you. It is difficult to profile the person who will betray, some times it can be sister or sibling who you trusted who will behave in a manner which is worse than the most unprincipled stranger.
A lot depends on the society we live in, if corruption is accepted as a way of life , in the longer run, the economy collapses. For some companies and individuals, the means by which they earn money are as important as the amount they earn.
But other individuals are less principled, the money and the fancy home ,expensive cars and gadgets they can purchase with it matter more.