You have scale, but where to stop?
The argument that if a company has scale (like GM), it should do IT in-house makes theoretical sense. However, when should a company, whatever be the size, stop obsessing over its size and see the business value of doing things in-house? It's like if you are very rich, will you wear high branded clothes, ask these designers to make clothes for you, or buy a cloth making factory, or start farming of products to create fabrics, etc. I mean where will you stop? Looks like people are saying if your application has a business logic, it is strategic, if it does not have business logic (email, collaboration) it is not strategic. No one talks about the people aspect. If you have good people, with decent enough system you will be a good company. You can put any business logic in application, keep them in-house, if your people are bad, you won't succeed. Therefore, it's not about what applications you keep in-house or outsource, it's about what your people do with those applications.