Who's dictating to whom? Michigan and Florida delegates

It strikes me as ridiculous that the political parties are trying to dictate to the states when they can hold their presidential primaries. By refusing to seat the Michigan and Florida delegates, the Democrat Party is disenfranchising the voters of Michigan and Florida. Both states ought to sue the Democrat party for disenfranchising their voters. The alternative of redoing the primary elections is significantly expensive. Perhaps Florida and Michigan should hold new primaries and sue the Democrat party for the costs involved. Similar reasoning applies to the Republican party, although it only cut each state's delegation by half.