No, in Europe economic rights are not always transferable, either. The classical example is the German Urheberrechtsgesetz, which does not allow for the transfer of either moral or economic rights . General practice is to grant the publisher a right to use the work (which can be exclusive or non-exclusive, perpetual or time-limited, etc.).
This is a subtle, but important distinction. Because such a grant does not entail unlimited rights to relicense the work and the author retains a number of unwaivable rights associated with the work. (German law intentionally aims to protect authors against various exploitative practices by publishers, making it very difficult for authors to sign rights away.)
The Berne Convention does not make it necessary for the signatories to allow for such a transfer, either. It only says that if economic rights can be transfered, moral rights remain with the author.
Also, moral rights most definitely apply to computer programs in many jurisdictions.
There are also many jurisdictions where moral rights are excluded to computer programs. Moral rights on computer programs are usually limited to "practical" rights like claiming being the authors. It's not really in opposition to the transfer of economic rights.
You are correct about the German case for moral rights but that was the main issue with the FLA. The FLA was mainly designed by a German lawyer thinking about his national legal framework.
In my perspective, we should avoid the over-legalization of (free) software development. And transfer of copyright/"patrimonial rights" is one of them, there are many way to exercise your rights as a free software author. I sponsored and supported for many years the FSF but I personally think that they made a big mistake, they underestimated the capacity of the "copyright mess" to secure free software (the Linux kernel is one of the example, you won't be able to find all the authors if you want to change the license to a non-free license). I know that seems to be a contradiction but as free software is relying on copyright, you can use also benefit from the multiple ownerships from the same artwork/computer program to secure free software. A single entity and a transfer of ownership can be even more risky...