So a thought on why attackers make "flawed" ransomware. They want to get paid as soon as possible, and a target pays a potentially heavy opportunity cost for noncompliance (waiting for someone to break the rw). The opt-outs are already not going to be "customers", and the "customers" you do get would pay even if they were only going to be locked out for 3 months. You get no extra money for making unbreakable ransomware

Edit: this may be similar economically to the Nigerian prices' aversion to English class.