There's controversy about the fact that if you wanted to change your party affiliation in New York in order to vote in the primary of your choice then you had to do it way back in October. That's ridiculous. But, having said that, I really don't like open primaries. These are contests in which members of the party choose delegates who then vote for the candidate. Also, plus, superdelegates. Sure a case can be made that the whole system is stupid, but the part that isn't stupid is the notion that these aren't elections in the normal sense. This is a process through which party members choose a candidate.
As I said, I think New York's deadline is ridiculous, but requiring people to make the effort to switch parties a week or a month out isn't. And in closed primary states, don't be an idiot and register as an independent. Nobody cares. You haven't stuck it to The Man by asserting your independence. You've just made your life harder if you ever do want to vote in a primary. New York is a bit different because the Working Families Party does manage to throw some weight around (or did until they endorsed Cuomo), but otherwise...