I've coded/supported a number of admin tools for a number of large companies (banks, telcos, etc) so I'll take a stab at "why" First, god mode can be implemented cheap and fast. God mode also makes day to day support easy as admins/support staff can do just about everything fast and easy - so they typically love it and will often fight to keep it. More than once I have had managers turn down proposals to tighten up security because of the cost and false beliefs that because the tool is behind a firewall, better security is not needed. Taking a schedule and/or budget hit to implement tighter security is not going to get them a promotion or bonus. Sad but true. In the vast majority of cases I've seen, paying for security improvements becomes incentivized for managers after their company gets burned by a breach.

Also, admin tools are often "afterthoughts", there is usually a motley collection of them, and often considered as an expense/cost to be minimized and not a revenue generating asset that gets more budget and attention.