You do make a good point about DRM and it's restrictions. These restrictions could still face "Fair Use" challenges in court in the future, and I would hope that the publishers would loose if they their DRM goes far enough to restrict fair use provisions of the copyright laws.
Still, there are costs involved in creation and production that limit how low the product can be produced for and still be a profitable business. If the electronic format cannot find a price point that will be profitable and the market will accept then it's success will be limited as a main stream format.
True. But publishers have to understand that people do not make buying decisions based on the cost of producing a product; they decide if the price is right based on the worth of the product to them. If they price e-material the same as or higher than printed matter they need to eliminate DRM so that the resulting product is at least equal in worth to consumers.
Note that if fair use applied to the DMCA that wouldn't eliminate the use of DRM - it would simply prevent legal liability to those who bypass technical measures (and maybe to those who provide software to enable such bypassing, but maybe not) to enable fair use.
It's bad enough that consumers perceive electronic goods as having lower worth due to their incorporeal nature - publishers are actively reducing the value of these goods while (in some cases) charging the same as for physical media.