The big advantage of using OSPF over BGP is during a network outage. OSPF can have extremely fast convergence due to the authoratative/hierarchal design, where

The big advantage of using OSPF over BGP is during a network outage. OSPF can have extremely fast convergence due to the authoratative/hierarchal design, where as BGP is decentralized and it takes time for network changes to propagate. Additionally, BGP is not always available on layer three switches, either due to licensing (I've seen BGP excluded from basic licenses) or just not supported by the vendor. Finally, OSPF is a lot simpler to setup and secure (everything could live in area 0 without the world ending), whereas BGP requires some decent architecture chops to make sure you don't create suboptimal routes or loops. Most places run BGP at the border (ha) and OSPF on the inside, this gives them the agility of BGP with the convergence of OSPF.