I tend to use the phrases "unjust discrimination" or "prejudicial discrimination" when talking about the sort of discrimination that ascribes negative or stereo

I tend to use the phrases "unjust discrimination" or "prejudicial discrimination" when talking about the sort of discrimination that ascribes negative or stereotypical characteristics to a person based on their membership in a class. But discrimination on its own is a neutral action, and as you point out, being discriminating by judging things on _relevant_ attributes is perfectly legitimate and often a mark of wisdom. So I would reject what you say about interpersonal relationships being the only area where being discriminating is laudable. Employers are discriminating when interviewing job applicants -- but hopefully, they are practicing appropriate discrimination, and weeding out people based on their skills and capacity to do the job, rather than inappropriate discrimination, based on a prejudicial reasoning. Similarly, consumers are discriminating when they look for products or services that are of high quality, and there's nothing wrong with that.