Why does mergeActions add default disruptive action even when action.Key is block?

[mucsbr]

Issue Description:

In the mergeActions function, the code logic skips over the rule’s block action and always appends the default disruptive action when merging actions. Specifically, the following code:

if action.Atype == plugintypes.ActionTypeDisruptive {
    if action.Key != "block" {
        hasDa = true
        res = append(res, action)
    }
}

Even when action.Key == "block", the system still adds the default disruptive action in certain cases. This is a bit confusing to me, as typically, if a rule explicitly specifies block, it should execute that action, not require the default action to be added as well.

My questions are:

1. Why does mergeActions add the default disruptive action even when action.Key == "block"?
2. What is the intended purpose behind this behavior? Is it to ensure some rules always execute a disruptive action, or to prevent potential misconfigurations?
3. Could this logic lead to unnecessary duplication of actions or affect the expected behavior of rules?

I would appreciate an explanation of the reasoning behind this design decision.