Should Equalizers make a comeback?

You would think the "straight wire" crowd would be discussing the systems of the various mastering engineers. Every component injects some "eq" naturally. Some components are "biased" a little warmer (Marantz comes to mind). Many people pick components (mostly) for their particular sound. So really, it's the same as using an EQ

Every time I use tone controls to tame highs or boomy bass,
something sounds fundamentally wrong. As soon as I take the preamp tone controls out via the defeat switch, a level of distortion just disappears. The same thing happened when I used a high-end digital equalizer at one time. This happened with various speakers and headphones. I avoid them whenever possible. They sound good in theory (and I use them on my integrated amp to cut the treble on for my TV, but that's just TV, so who cares), but it seems like a false hope to me.
My great expectations for equalization have always been dashed.

I sympathize with Rgs92. Realizing equalization that does more good than harm is difficult using the products currently available. The market simply has no interest in the subject. It would be fairly easy to design a module which would measure the in-room response at the listening position and then correct it. The problem is simply that the market for such features is too small to spread the R+D costs sufficiently. Some HT receivers do a fair job (HK) of gain matching using a mike in the remote control. A little more development could include low frequency equalization as well. Mid and upper bands are very tricky as masking effects, etc. come into play.

"So really, it's the same as using an EQ"

No it isn't. EQ involves additional stages, capacitors in signal path etc. (some form of signal processing) Let just say that it doesn't add to clarity.

Deficiency of recording is usually much more complex than simple tone controls that would perhaps do more harm than good. Imagine that you listen to Jazz trio and acoustic bass was recorded a little too strong. How can you correct it without affecting sound of the piano's lower registers?
That was just a trio - imagine complexity of an orchestra.

If the problem is room acoustics then fix it. If recording is made poorly don't buy it. If system lacks something - find better match/synergy.

I also suspect that the need to correct is somehow related to lack of system's transparency/clarity. With inexpensive receiver and speakers, I had once, I often used tone controls to get better clarity (unmask). With transparent amplifier and speakers now I don't need it anymore - everything sounds about right. Market confirms my findings - all cheap amplifiers have tone control (often EQ) all or most of expensive don't.

If the music has particular sound then I assume it was intended to sound that way. When I am at the concert I don't climb the stage to adjust their amps or PA system.

I run two CD players through my main system. One of the Players runs through a Equalizer first.

I put all high quality recordings through deck one and the lesser recordings through the second deck.

Best of all worlds.