There are some other ones that personally bug me that I found Bernie pushing in a direction that I found more palatable.
Obama using the espionage act on whistleblowers while at the same time strengthening the NSA for example. That one still mystifies me. Obama has also deported more people than any other president. The list goes on, I'm sure you've heard it all, but Bernie's positions on all of these felt like a breath of fresh air to me. Hillary moved on some of these issues, and didn't on others. Sanders and his message really affected me and I think he made a lot of great points in many areas.
On the side of Hillary supporters, I can kind of imagine Sanders as coming out of nowhere, busting down the door saying something vaguely sounding like "Screw this, we're doing it my way now! Buckle up guys, it's time for a revolution!" then promptly losing, and then leaving a number of bitter people in his wake. I can see how it's not exactly a pleasant experience for those on team Hillary, especially if Bernie's message didn't particularly resonate with you.
However I agree with what Bernie himself did at the end of the day personally. He didn't try to run as an independent or anything crazy, he tried to energize people to support the Democratic party and run for local office, and he's stood up against Trump. Because of his message he wasn't a particularly good surrogate for Hillary, but he tried. However, the goal hasn't been to be scorched earth, but rather try to evolve in a fashion that supports both sides and wins elections. That's my personal hope at least.