Do we charge people and send them to prison for coughing in public while suffering from influenza?
The difference here is that influenza does not typically give everyone it infects a slow and painful death.
Malicious intent isn't necessary. He acted in blatant reckless disregard for the fact that he was quite literally killing people with his actions so he's quite obviously criminally negligent and thus guilty. Of an offense less than first degree murder, yes, but still guilty.
He wasn't honest, he wasn't upfront, he didn't always use a condom. By your own standards, even, how is he not criminally irresponsible here?