Trump crossed the line when he criticized Nordstrom.  A businessman politician has an ethical obligation at the least to put his holdings into a blind trust when he enters office and Trump has shown no inclination to do so.  

All of the various Trump offerings are manufactured offshore something that he is castigating other companies for.  

Any business would dispense with a non-performing product or service, boycott or not.  It was a simple business decision on the part of Nordstrom and others.

There is no indication that a businessman would make superior candidates; probably the reverse as they are oriented to maximize profit irrespective of the common good.

What is most likely to set a "terrible standard for years to come" will be Trump's appalling supreme court appointments.