Composite video is a different issue than phono preamp. The phono preamp is a question of audio quality, while the composite video input is a question of compatibility and legacy support. There is no way you could connect a VCR or other video source (like my SMS-1) through a processor without a composite input - there's no outboard "transcoding box" that will make it component video. If you remove it entirely then you are telling your customers "I don't care if you want to hang on to that VCR, old game console, camcorder, Video iPod, or the SMS-1 that we sold you - you can't use it with our processor." That's a touch rude...

Here's a loosely related question: "why do Blu-ray players typically have composite outputs?" (After all, who on Earth is going to buy a Blu-ray player and hook it up to any display that only has a composite video input!?!?) The answer I've gotten is that leaving a composite output helps in troubleshooting customer setups by eliminating resolution compatibility and other issues.