Despite knowing about the usefulness of saturation and its improved distribution of frequencies with distinguishable character, they could only do so much. Character is an important aspect of audio tracks, and equalizers could only do so much to manipulate them.
The most important aspect of audio recording is to get every sound correct during the pre-production process. Fixing the sound in the mix through an equalizer or a saturator will only bring minor changes. Attempts to improve things with a saturator or equalizer will only make things worse.
For guitarists, a treble-sounding guitar might not be for everyone. However, it does not mean that lowering the treble frequencies in the equalizer will produce the desired results. Remember that equalizers only attenuate and boost frequencies, which can shape the sound according to the context of a song. The actual sound of an instrument depends heavily on the equipment you use. For guitars, the body and pickups used has a big say on the sound of the instrument. The same goes for drums, basses and other instruments.
Equalizers must be viewed as sound filters, nothing more. Designated filter plugins are designed to produce effects using automated equalizer settings. They only do an effect, but never actually re-shaping the root sound of the instrument. So, do not attempt to fix it in the mix.