The stronger case against a cultural boycott of Israel is based on consistency, proportionality, and history. That supporters of this boycott seldom focus on China or Syria or Zimbabwe---or other genuinely illegitimate regimes that systematically violate human rights---underscores their bad faith. Boycotters are not trying to send the specific message, "We object to your settlement policy in the West Bank." What they’re saying is, "We consider your country so intrinsically reprehensible that we are going to treat all of your citizens as pariahs." Like the older Arab economic boycott of Israel, which dates back to the 1940s, the cultural boycott is a weapon designed not to bring peace but to undermine the country.
I don't like to scream "antisemitism!" but the singling out of Israel by many of the left is something that always strikes me as peculiar, especially in the face of such gross human rights violations in countries as China, Cuba, North Korea, Venezuela. Yet you don't often hear them complaining about those countries. Guess what they have in common, besides executing dissidents?