Or it speaks to years of cost benefit analysis and outcome of someone doing this maliciously is so benign or so embedded within a trust chain that there's no be

Or it speaks to years of cost benefit analysis and outcome of someone doing this maliciously is so benign or so embedded within a trust chain that there's no benefit to closing that particular hole. Not that I have any expertise in this particular situation, but not every 'threat' when armchair analysed in isolation is a threat when put into its correct domain and context.