Modern Linestages

If simplicity also meant inexpensive it would be nice. All to often something that is very simply made, almost elegant, is a work of extreme craftsmanship. A simple circuit will do but when you extend that to better/purer resistors, capacitors, etc. etc. and so forth, simplicity adds up to a lot of costs real quick.
A Swiss watch is a thing of beauty, not a lot of moving parts but try getting one for the cost of a Timex.
Sometimes paying more gets you more and sometimes it is a case of a fool and his money are soon parted.

Mikelavigne stated it very well, I don't care how the piece looks I care about what the piece does. If it makes music then YEA everything else is an afterthought.

Trebejo, Your point could just as easily be lodged at BMW, Mercedes and Rolls Royce owners. They haven't done an especially good job of getting their costs down and spreading it to the masses either. Like it or not there will always be a better something or other. Scarcity is one thing that drives up cost but not the only one.
We all can't drive around in rich luxury cars but I do not bemoan those who do. We all cannot have totally exotic systems that mystify us as to how is this possible.
The implementation of simplicity is rarely inexpensive. Getting rid of impurities in resistors et. al.,, costs, design, R & D etc all add up. Then there is what will the market bear?
A tree limb with a line and a hook can work for fishing but a fine flycasting rod and reel is a whole other story.

First, thank you Swampwalker for the kind remarks.
An example of what the OP may have intended is the
Conrad-Johnson Classic Preamp. No frills, no remote, just a good product for two channel. Being sold at a reasonable(according to audiophile standards) price.
So yes it can be done, simplicity whether in audio or life never comes easy.