Summary of shortcomings
Many times the requestors of non-aggregated PI IP address space and AS numbers are not aware of these implications and lack sufficient technological background knowledge to qualify and quantify the impact on themselves and the Internet in general
Many times only one or a subset of one of the reasons for AS based multi-homing is given by the requestor
Unfortunatly in these cases the cure of AS based multi-homing is often worse than the disease of being single-homed