What are the arguments for creating you own ORM layer? [closed]

Question

The advantages of ORM are pretty clear. But I noticed that some companies prefer to build their own home made ORM. Why?

Answer 1

There are only two arguments that I can possibly see for ever hand-rolling your ORM (and these have happened to me in the past, which forced me to write my own):

1. The company refuses to use Open Source software because of liabilities they assume might creep into their application.

2. The company refuses to spend money on a commercial ORM.

Any other argument (like the quality of Entity Framework is too poor for us to use it) is completely moot. No matter how bad Entity Framework (or whatever other ORM you may be referring to) is, you're not going to come close to the robustness and reliability by hand rolling your own.