Why is loudness compensation missing from "mid-fi"?

Very often I like to listen at low volume when writing or trying to fall asleep. Without adjusting loudness, a lot of my favorite records sound faint and hollow. My current setup lacks loudness compensation, so I simply fiddle with the tone controls, but it's a crude "solution" and a bit of a nuisance. I've been researching my next upgrade, and I find it strange that some entry level equipment has loudness compensation (e.g. Yamaha A-S301), as does some high end equipment (e.g. Accuphase), but usually nothing in between. (e.g. Yamaha A-S1100). Why is that?

Every time I'm about to pull the trigger on an A-S1100 I talk myself out of it by telling myself I'll still wish I had the Accuphase for loudness compensation. It's annoying, because my setup really doesn't warrant an Accuphase — or maybe it does, if I can't find what I want elsewhere?
Low level listening is always subject to the Fletcher-Munson contours, and that's certainly NOT remedied by bypassing tone controls. It's not a synergy issue at all...it's a perceived tonal issue relative to low level sound. Note I rarely use my Loki EQ unless some recording seems to really need some adjustment...still rare.
+1 @wolf_garcia
The alternative to Wolf's point is to get a pair of speakers for late night listening, and another for full volume.  Just what I need, another pair of speakers.... :D :D
Wolf_garcia, this is exactly what I use my Loki for. It’s on a processor loop from my preamp. I rarely use it as an EQ except for "loudness" needs later at night and/or low level listening. Works like a charm!
The loudness contour as they use to call it was used to correct the low sensitivity of the ear when listening at low levels. Some had compensation for low and high frequencies, others just low frequencies. This switch irritated many salesmen back in the day, saying too many people abused it instead of using it for what is was designed for. I believe the Mid-fi Outlaw receiver has this compensation. Good product from what I have heard. $800 retail, Stereophile class B component.
Get a Schiit Loki..