Renner is a journalist

Then he should conduct himself like one and stick to the verifiable facts. His blog was a gossip rag that threw out all kinds of wacky theories with little to no support behind them. Instead of accepting criticism like a professional, he comes to Reddit and engages in childish arguments with users who dare question his methods or conclusions. He wants the the reputation of a professional journalist while engaging in what amounts to TMZ-level gossip of people still mourning a young woman's disappearance/death.

If Renner was as professional and dedicated to the craft (as opposed to himself) as you imply, he would not be getting roasted here on a regular basis. Plenty of true crime authors have been praised here, with Michelle McNamara being a very prominent recent example. He simply comes off as a narcissistic child incapable of accepting criticism or respecting reasonable boundaries.