Why does CD suffer on most universal &dvd players?

I was just wondering why the redbook CD performance on most stock universal dvd players and even on normal dvd players suffers in comparison to dedicated CD players in your opinion?
Would it be because the playback lasers may be different or focused differently, more complex circuitry for the video and/or SACD/DVD Audio sections causing interference with the sound of the redbook cd circuits, the DAC's having to perform more tasks, possiblly cheaper grade parts for the cd circuits to save costs, a combination of the above, or something else?
Thanks for your opinions.
Unless the player has separate lasers for CD and SACD/DVD-A, playback is compromised. As you mention, focusing paramaters are different.
I'm guessing that it is because you are spending money on features (universal playback, multi-channel outputs, etc.) requiring manufacting cost to be spent on add decoding chips, etc, instead of spending the money on sound quality.

It's the "Swiss Knife Syndrome". Yes, a swiss knife will open your bottle of wine and remove a flat blade or phillips screw, but it won't do it as well as a simple cork skrew or screwdriver.....


Chapter 8 in Robert Harley's "Complete Guide to High-End Audio" goes in to this in depth. The entire chapter is dedicated to digital source components. He does explain why it is best to go with a separate dedicated CD player vs universal units unless you're spending in excess of $5K. It's also best to choose a single disc player and avoid the multi-disc changer units. Much has to do with dedicated DAC's and features only relevant to CD reproduction without video circuitry, etc. There are many great single drawer high-end CD players under $1K. Hope this helps.
I felt that way about the Marantz, Sony (SACD player not universal), Esoteric players (not looking for a flame war, but 95% of my collection is redbook so that is how I compared them)... I did not feel that way about the Theta Compli (which I bought) and the Ayre Universal players.