I still don't think alot of people get it primaries are NOT part of the general election, there was a time when normal people had absolutely no control over them, so relatively speaking we are doing pretty good these days. The primaries are way for the PARTIES (not people, but political entities) to choose who will represent them in the general election. Why shouldn't the leadership of the party have more say than everyone else? It is like saying all stockholders should get the same vote in a company, or students at a university should get as much a vote as the administration. The leadership of the party wants to choose the best canidate to represent THEIR values, not anyone elses.
The thing is with this two party system we have everyone makes it seem like "Republican" and "Democrat" are somehow mandated by law or something like that, in reality they are just a group of like-minded people who decide to work together, there is nothing saying you have to vote for either or them, anyone can run for president if they get enough support, you can vote for anyone you want to no matter what party they are (even people with no party). The fact that there are only 2 parties with any real power in this country is because thats how people voted, if you don't like it, or think the parties are corrupt in how they choose their delegates than vote for someone else, nothing saying you have to choose one or the other.