If you want to drive a car or play a musical instrument or bake a cake - you need more than just the equipment and ingredients to do so. The how-to knowledge is key, of course. That and some practice. (Especially in my kitchen!)
Why would you bother to roll out tools like antivirus, anti-malware, endpoint security, email filtering, DNS protection, data loss prevention, geofencing, firewall traffic shaping, etc.