You have to differentiate between individuals deciding for themselves to go elsewhere and organized boycotts designed to ruin a person. I would hate to be a minority business owner in a society that condoned flippant use of organized boycotts.
Individuals only have power against large organisations when they collectivise. That's why big businesses are (often) anti-union.
If the imaginary Christians-Against-Internet-Explorer decide to boycott IE10 because they believe the new MS CEO is Muslim, no one is being forced into joining their misguided crusade, are they?
So, what is an organised boycott? It's individuals using strength in numbers.
The myth we're sold is "one man can make a difference." That's rarely true. Many people, acting as one, are what makes a difference.
There was nothing organised about this current situation. I don't remember anyone forming The National Committee Against This One Guy We All Hate and then asking me to pay dues.
Nope. Just a bunch of individuals expressing their collective economic might.
You're right, organised members of the KKK aren't going to eat at "Hamza's Hummus Hut" - but neither are individual racists. If they want to run him out of town - I'll take a stand against that. If they don't want to eat there, I won't force them.