Why did Mueller turn in his report before the investigations were complete?

[emmaverybo]

12. He's not our hero or savior. That was not his job. He gave a blueprint to impeach and a case

that can be charged when Trump is out of office.
Going straight to the press would have discredited him and the process.
Worse, such a move would ensure the report’s findings and evidence would be inadmissible in any case stemming from them. A Mueller press conference would be the best way to getting a case thrown out or seeing its defendant be acquitted.
This was not a Mueller vs. Trump investigation, but one carried out under DOJ. In fact, if there ever is a case it will not be called Mueller vs. Trump, but U. S. vs. Trump. Barr was the spinner in the works.

In one regard, Mueller's service qualified him as a hero, literally, which is perhaps what you pick up in discussions around him.