No doubt, and I voted for Bernie, but Bernie made his bed, frankly. He spent a lifetime in politics often proudly NOT-A-DEMOCRAT, then decided to run for POTUS, recognized his own "party" doesn't exist, gave him 0.00% chance to get elected, and so opted to freeload off the Democratic party that he's done actually nothing to support over those decades in politics.
Anyone thinking the party leadership is going to ignore that and treat him like an actual Democrat is not realistic and is quite frankly not very bright, especially against a person like Hillary who had spent decades working with the party leaders, raising money, supporting Democratic candidates all over the country, etc. So I actually think he got as fair a chance as he deserved from the PARTY itself, and he just came up a bit short. That's too bad, but it's also reality.
Besides, Trump did roughly the same thing but on the GOP side, got the same general treatment from the party leadership (actually FAR worse in my view - no concerted #NeverBernie effort on the left) and overcame it. Good for him, but if he'd lost, I don't think it would have been fair for him to whine about the Republican PARTY not supporting him - he didn't earn their support.