First off, when you hear people say "dig everything", they .... of course .... mean "everything except iron" usually.
And to answer your question, even if someone is in a "relic mindset" and is going to dig it whether it reads foil, or silver dollar (and everything inbetween) it is still fun to have the tones. And subconscious priority assessments are going on, when you have the TID and bells and whistles. For example
One time a friend of mine and I were hunting a furroughed field where 1790s to 1820's activity/camp/village had gone on. Naturally we were in a "relic mindset", digging all. He was using a machine with no TID and had his settings down to where anything above iron would come in. I, on the other hand, was using an Explorer. But I was in ferrous with the screen wide open, and was "digging all" too. However, at the end of each day's hunt, I would invariably "spank him" 3 to 1 when it came to coins and buttons (the preferred targets, of course). However, when we'd go to count our actual targets (can slaw shredded by tractor plows, etc... AND "period" targets), we noticed that our target counts were approximately the same. Yet my coin counts (reales) and button counts were always better than his. He accused me of "cherry picking" and passing some of flittier cr*ppier sounding little aluminum turd things. I assured him that I was not "cherry picking", because I had my screen all the way open. Nor was depth an issue, since we had the same target count #'s, and depth isn't an issue in furroughed fields anyhow, since stratas are all jumbled up. Thus both of us were very confused why I kept spanking him on the better/desirable targets.
The answer finally occurred to both of us: Since this was a virgin site when we started, and since targets were EVERYWHERE for the picking (ie.: 100 targets in a few hours hunt), we realized that what I was subconsciously doing, was favoring the "better sounding" targets. It wasn't on purpose, mind you ..... but when you have many clear round-coin sounding things to choose from, vs whispy bi-metal flaky cr*p sounding things, you subconsciously will start to favor the better sounding things. But a monotone machine, where every conductor sounds the same, you have no such ability (whether intentional, or subconscious).