I admit the MT brand of ROS has had its fair shares of big issues. Thou I still think the platform - to an extent - has a powerful programmatic interface. Despite it being ‘low-cost’ and easily misconfigured by the average layman or Dohn Joe. Winbox, too, has had its share of vulnerabilities that - if not secured properly - is easily exploitable. All true. Thou, in my opinion, still does not think it does not deserve a rudimentary fair position in your FW comparison chart. Yes, the learning curve is not low. That has is up-and down-side of the ROS being flexible to configure. In exchange for requiring a ‘somewhat’ steep learning curve in the beginning.
pfSense (my comparison) had a steep learning curve, too. It was easy to get working with one LAN and WAN interface. All things after that, policy routing, multiple VPN tunnels + NAT, IPv6-PD over a PPPoE internet access, multiple VLAN’s and securing access properly between VLAN’s, in my honest opinion had their fair share of a learning curve (for me).