Tape-in and Tape-out ports


Why do so many preamp manufacturers still provide Tape-in and Tape-out ports? I doubt if they expect folks use them for hooking up a tape player. Some even still have a tape monitor switch on the front panel. How do you guys use these ports and has anyone noticed a difference in sound quality if the tape-in port is used for something else like a CD player, etc.? If the tape-out port is just like another output, e.g., drive a separate amp or a powered subwoofer, etc., why not just call it Output?
Been meaning to ask this question, albeit it might sound rudimentary.
128x128kalali
Me too Don, for my Stax headphone amp. The old tube version of the amp had a pair of output jacks, for returning the signal to the pre. 
I have a question that I'm told pertains to tape in and tape ports: I was advised that I should try to use tone controls in my system and see if I like the results. I have an Adcom pre and was told it could be inserted into my system, and "play" along with my existing Audible Illusions Modulus 3B preamp. As I understand it, the Adcom preamp would only be used for its tone controls and the way to accomplish this is to use its tape out ports.

Is anyone familiar with how to do this, i.e., how do I set the signal path? Is it source to Adcom to AI to amp? Or souce to AI to Adcom to pre?