Is bass the most important frequency band?

 What a balance we must achieve to please ourselves. And on top of that, mood matters, damned age matters now, then there is the environment for listening. Assuming that all goes well I can't top the experience. But  it is just about anywhere in the audio spectrum (except treble, which I just don't hear well anymore), it has to be right for me. Midrange can make me cover my ears, 'bad' bass loses my interest, and even noise if it is too high makes me walk away. If it don't sing, I'm walkin'.

I don't care much for bass compared to the midrange frequencies. 
I'm one of the few .7 magnepan users who don't feel the need for a sub. 

I think many have this right. Because the room is in essence a bass instrument the variables involved make accurate bass difficult to achieve.
cd318 is also very right. "most systems don't even try." This is for good reason. IMHO no bass is better than bad bass. 

I have no problem enjoying music with no bass but you can not reproduce the "Live" experience without it. One can argue about the best way to achieve accurate bass but many residential spaces preclude making accurate bass and at best you might be able to get it at one location in the room regardless of what equipment you use and how you set it up. Using multiple subwoofers definitely helps but you still have the entire room and it's contents vibrating at various low frequencies screwing things up. Room control helps but it can not overcome poor room acoustics and items resonating and buzzing. For fun get a test record or CD and play a 40 Hz sine wave. Turn up the volume and listen to what happens. The lower you go the more items will join the symphony of buzzing and rattling. Items ringing add a higher frequency halo to it. This is usually masked by the music so you only hear the loudest problems under the right circumstances. It took several months to stop my theater screen from acting like a tambourine. Tip of the day, get a roll of butyl glazing tape from your local glass company. You can stop any rattle with it! 

Even the most intelligently designed rooms will have some problems. If you want to know what your situation is like take snapshots of the room at various locations with a measurement microphone. You can get a mic and a complete computer program for $300. It is the best tweak you could ever buy! Ideally you should get the same frequency response at the various locations. What you will get is wildly different curves. 10 dB swings are the rule and 20 dB swings are not unusual. This will happen even with a swarm system but to a lesser degree.

Unfortunately, there is no acoustic treatment that can overcome a bad room and the best solution is to limit low bass so that exaggerated low frequencies do not overcome the midrange. IMHO there is no one most important part of the audio spectrum. Midrange sibilance is every bit if not more aggravating than bad bass. I personally can't stand a system that is too bright. Old age will fix that problem. But, I have to say that hearing a system with great bass is great experience. You get that same rush you get at a live concert when the band lights up.   

I look at it this way, low frequencies are less harmful to your hearing than high frequencies. That's why the majority of people lose some of their upper frequency hearing as they age. Hence, at 67, I favor bass. A little more bass, less treble, I can therefore keep a decent volume up and not get hurt by the high frequencies as much. Win, win. Just me.