Rejecting clients when you have enough is a sound business decision. Some clients are too annoying to serve. Some clients don't want to pay. Sometimes you have more work than you can do... It is easy to think when things are bad that you must take any and all clients (and when things are bad enough you might be forced to), but that is not a good plan and to be avoided. You should be choosing your clients. It is very powerful when you can afford to tell someone I don't need your business.