The boycott is specifically about the occupation. Other countries do awful shit, but the PACBI boycott is a response to a unique situation. A vaguely similar parallel at this point of time would be Ukraine, and plenty of people are boycotting Russia - or Russian acts are being let go from bookings, as we saw with Nina Kraviz at G22.
He discusses his politics in interviews fairly regularly - and it occasionally slips through in The Red Hand Files. The most recent interview I read he was bigging up Andrew Sullivan.