And how many companies today are managing costly, legacy software solutions that they built in-house years (decades) ago? Every one I have ever seen.

The same logic could be used to justify duct tape software across the enterprise. There is some point where the cost-benefit leans in favor of outsourcing. Institutional knowledge may be under-priced by today's business execs, that is certainly possible. But we also shouldn't build a homegrown solution for every problem.