I think everyone agrees that countries should do actions that support their politics, and should not do actions that are against their politics. That's not hypocrisy, that's just holding a political opinion.
But if you switch the issue to legality, that's a different issue. "Legal" is an objective standard that's independent of ones' political beliefs. Or at least it should be, a lot of claims are made that seem based more on personal opinion than actual law.
So under what circumstances are a blockade legal? Does the Israeli blockade fit that definition? Would a similar blockade by Lebanon or Syria also fit that definition? If you're willing to look at the law and make a determination based upon the law, then you're capable of objectivity.