Tim hit the nail on the head. Maintaining statics on a large network would become a huge problem. Human error will eventually occur. The network scenario I am speaking of is DSL/Cable type setups, where a customer could move from router to router(DSLAM/CMTS) due to capacity re-combines. Utilizing a dynamic routing protocol makes these types of changes easier to digest.
Just to be perfectly clear with the scenario I was referring to (L3VPN with all remote sites hitting provider router) that Tim was responding to.. The kit is all managed - customer has no access to it. I should have mentioned that before, as it's a pretty key point to the example, perhaps it was thought the customer could touch it? What is needed is simply one step above statics so the provider does not have to maintain them. Loops or hop count are a non-issue, and the customer sites have no redundancy. It's not even a requirement to have fast convergence. All that is required is to have the CPE say 'here is 10.0.0/24', or at a later date, '10.0.1/24' without any work on any other equipment. Nice and easy. RIPv2. Arguing that BGP should be used over RIPv2 in this scenario becomes interesting, as BGP would offer no real advantages and requires further configuration in most cases for each site deployed. It also introduces more overhead for the carrier, the same with OSPF and IS-IS. In other scenarios - of course choose a different protocol - but for this one, I think its a good example for the OP as to why RIPv2 is still used.