This anti-pattern is predicated by two underlying truths.
1. The gatekeeping behavior is individually beneficial even if they are globally detrimental.
Blocking access costs nothing, and may benefit them as people pay the toll to gain access to the resource. They may not be Machiavellian schemers. It could just be mismatched incentives or a departments only way to deal with the 'externalized costs' imposed by other departments. For example the account manager may guard their customers because an ambitious sales team is incentivized to aggressively cross sale, and the sales team does not get dinged for souring the customer relationship.
2. The gatekeeping behavior may be globally beneficial even if it is annoying to those who must go through it.
Raising the bar for access to a valuable resource keeps that resource from being squandered, even if it is more frustrating to use when needed. It is why we have to break the glass to get to the fire extinguisher. Anyone who's been in a position where they are the 'valuable resource' knows that there is a constant cacophony of poorly thought out requests, meetings, proposals, demands, etc... And without some means of filtering, or pushing requirements back to the requestor, valuable time is wasted.
Designing an organization to avoid T1 gatekeeping involves identifying why this behavior benefits the individuals involved, and following that thread to find the root cause. Directly discouraging T1 gatekeeping without changing incentives is the management strategy of Sisyphus.
Most organizations could benefit from an increased and more formal approach to T2 gatekeeping. It can go too far, but I've observed many teams held back because everyone is informally asking one or two experts for all the answers.
