80% of our attention is spent on dealing with 20% of our worst customers.
80% of our revenue comes from 20% of our best customers.
By spending that much time on bad customers, we rebuild our business to cater to bad customers - thereby attracting more bad customers, and leading to our inevitable downfall.
But, if we spend most of our time on good customers, so much so that the 20% of our best customers became 100% of our customers, then our income would quadruple.
You are valuable as a person and as a business. There's no reason to put up with other people's bad energy.