Similarly, the type of functionality that you want (which, let's face it, is the ability to remix a movie soundtrack), is more practically done with an inexpensive mixing console.

And what is a mixing console but software, in the digital domain? Why should I have to buy an outboard unit, that works in the analog domain, when all the hooks for a digital mixer are already there?

The point is that I view the 990 as being built up of several hardware and software modules and I'd like greater control in how those modules are wired up, so their facilities are fully utilized. The supplied operation should be a default, or manufacturer-selected "product" made upon this platform. But, it is frustrating when the platform is not exposed as part of the product.

This philosophy would also permit those who do not like the UI to write their own, if so inclined, and not have to accept Outlaw's view of what is the most user-friendly.

Many of the choices made in developing a product on a platform are arbitrary and there is no guarantee that the manufacturer made the right decisions regarding how to put the bits together. This does not mean the entire design and architecture has to be exposed, but a few hooks would increase tha applicability of the platform greatly.

Not being "economically practical or legally possible" are valid reasons for not squeezing that functionality into home theatre pre-amp/decoders.

Except that applies to extremes of the philosophy of open design, and not to all cases of exposure. It would be folly for Outlaw to make Macrovision defeating configurable, for example. But, there is much they can do without such questionable bits.

This isn't something specific to the 990. There isn't a single HT pre-pro that has the sort of re-mix capability that you want. And that's not based on some rejection of a "particular philosophy", but just a matter of practicality.

Take a look at some of the image processing capabilities, particularly deinterlacing choices in Linux PC-based HTPCs. There are cases where the deinterlacing algorithm is plugable. DD decoding is also often available, making it a pre/pro in my book, though the legality of doing that is questionable. Finally, the difficulties of doing all this in software and not DSP firmware, are that a very powerful processor is required, which means a noisy fan, and all that entails.

No doubt the 990 is based on some type of platform. Exposing more of that platform would go a long way to understanding some of the more odd parts of the 990's operation and create the possibility for community-supplied enhancements, or if the platform was simply documented, but not made available at a lower level, informed suggestions regarding same.