First I do not want to start a Flame war, but I am have been working as a sound engineer in recording studios.
we have to clarify a couple of things.
1.
when you produce things in a studio you have so many sound altering devices that they are too many to mention.
1b.
so your job is to change original sound to "interesting" sound.
2.
studios pay a lot of money to have "neutral sounding " speaker monitors, so you have a reference to listen to
2b.
good sound is really personal, that is why you can hear difference between different studios or producers, we are all individuals.
3.
people tend to forget the importance of good quality MP3 ripping. compressed music is not Hi-Fi...it can be good and I listen all day long to it, but it is not High-end Audio reproduction stuff. very handy though.

Reproduce Audio
This is where things go wrong with people say NO to (good) EQ

you forget the listening environment.
to give an example, when you have been at a Rock show the sound probably was bad in the beginning of the concert ( as they cut time on pre-show sound testing ) it is also hard to test the sound without an audience, which affect the sound a lot.

this is the same scenario when you are in a car or in an airplane, or even in your living room, there is different background noise, and acoustics that you need to compensate for, even wearing most headphones ( if not totally removing outside noise)

I agree that you cannot use and EQ to compensate for crappy sound, headphones or speakers, that is where you should start, but and EQ do help ( used within reason ) to compensate an not perfect listening room, crappy speakers, personal taste, why shall you not have be able to personal sound, we all hear things different as ask a Dr specialized in hearing.

I also agree that most cheap built in digital EQ can easily create distorsion, so when using EQ listen carefully so it is within limits of what the pre-amp / hardware / software can do.

and a fact for most non-EQ fans....you can turn it off......

As I said in the beginning not here to start a flame war, just giving my personal opinion.

and if you could not guess, I am Pro-EQ