Samsung uses Android to sell chips: Samsung SoC, Samsung DRAM, Samsung AOLED, etc, etc. With Dell, well, it would be packing other people's chips and putting other people's content on it. So indeed, it's not a game Dell can play.
Dell suffers because the only innovation they every truly had was supply-line streamlining, but they've been totally blown away by Apple's Cook + the move to China, to the point that they don't have any advantages these days. They never bothered much with R&D, and now they are dead because of that.
It's hard to match google's prices on android devices when google is content to break even on the device.