Let's take these one at a time.
There's no question that Trump had an appeal to white nationalists. Why would anyone think this helped Trump? White nationalists are a very small percentage of the population. You don't win elections appealing to them. In fact, more voters were likely turned off from Trump due to the things he said that appealed to white nationalists. I know liberals want to believe what Hillary Clinton said, that half of Trump's voters were racists homophobes, but that's ridiculous.
Blaming the media is popular with all the campaigns. Every campaign thinks the media is covering the wrong stories about them and isn't treating them fairly. I'm sure the Clinton campaign has a point that they got a raw deal from the media. So does the Trump campaign. We often heard the complaint the media gave Trump so much free air time. That was because the viewers wanted to watch Trump. If you had an interesting candidate, they would've put Clinton on. The truth is that the stories the media covered, on both sides, were real stories and campaigns don't get to decide how they're covered. You need to overcome the media, not blame them.
They blamed James Comey. The surest way to prevent the FBI from influencing the election would be not to nominate a candidate under investigation by the FBI. No one ever had before. If Comey's letter had an impact, it was their own fault for Clinton doing the things that put her under investigation. Yes, the FBI recommended against prosecuting but the investigation was legit.
The Clinton campaign was afraid that the Comey letter burned them with Romney voters who found Trump unacceptable. When they were reminded why they hated Clinton, they went home. There's no way to know for sure, but Clinton did much better than Obama in Republican suburbs where these people live. The rural voters that Clinton chose not to appeal to didn't pay attention to the Comey letter and weren't going to be swayed. If Clinton does what Obama did in working class districts like Michigan 5, she wins Michigan, Wisconsin, and Pennsylvania.
They blamed younger voters. Clinton won them overwhelmingly but didn't do as well as Obama. The Clinton campaign team said that at the last minute they flipped to the third party candidates. That doesn't make a lot of sense. Look at the chart on this page. Johnson and Stein were getting 11% combined on September 1. That dropped to 9.4% on October 1. On October 24 it was 8.2%. The final polling number was 6.6%. Johnson and Stein actually got 4.3% of the vote. On the other hand, Clinton finished polling at 45.5% and got 48.0%. As with most elections, voters left the third party candidates for the candidates who had a chance to win.
Hillary Clinton lost because she was a bad candidate who ran a bad campaign. She couldn't hold onto to Barack Obama's share of the rural white working class vote. He didn't do great, but she did much worse. (Wait. If they're racists why did they vote for the black guy but not the white woman. They must be sexist. Even the female Trump voters) The campaign staff can blame everyone else, but it was them and their candidate who really lost.