My point was that you are not actively blocked or "discouraged" from making your own crypto implementation and submitting it for FIPS validation.

Of course, that will be more expensive and time consuming than simply reusing a previously validated crypto module. So, you could perhaps call that "encouragement".... but the idea of FIPS is to provide some level of assurance to the consumer of said solutions.

But there are cases where you desire to control your own crypto.