The comment section always have people informing if it is malware or not, besides; in that line of logic they would have to censor all file hosting services (those don't even have comment section)
Firsty, comment sections are usually full of noise and it's next to impossible to distill any valuable information out of it. Secondly, don't expect an average person to bother checking for potential malware.
Eh, the comment section very often contains people notifying everyone that a) the torrent contains malware, and b) the torrent does not contain malware. It's such a crapshoot. The uncertainty would put me off pirating as much if nothing else did.