Democratic Primary Schedule

I really don't understand the Democratic party officials complaining that Hillary Clinton is hurting the party by staying in the race. Did Clinton set the schedule for the primaries? I don't think so. If the party wants the primaries to be over by May, than they should schedule them so all all states and territories have voted by May (which I am completely in favor of doing) and not tell one candidate to drop out for the good of the party. It would make sense if Hillary only had ten or twenty percent of the delegates so far, but that is not the case so there is no good reason for her to quit.