It's was designed for the purpose I previously mentioned: as a way to prevent negligent gun handling. I don't know why that's such a bone of contention. Law enforcement's use of the feature for the purpose of officer safety is irrelevant. The original M39 wasn't designed for law enforcement, it was meant to be a submission in the aborted post WWII military pistol trial. It was then released for commercial sale when that didn't happen. It was a good decade after before law enforcement began to embrace it.

Like the Walther P38 before it, the DA/SA M39 was designed from a desire for increased safety over the single action pistols then in common military usage. The desire for a decrease in negligent discharges was the entire impetus for these design features. Many law enforcement agencies later found the mag disconnect attractive as a safety against a disarm, but that wasn't the original intent.

I honestly can't understand why anyone takes issue with this.