I have a great idea for a revolutionary new game console.  We're talking about some high-end hardware design here.  Let me break it down for you.  First, we're going to run the power supply through the proprietary RF switch.  Then we're going to lock down potential piracy with a flaky copy protection chip on every outdated cartridge that, as the console ages, will malfunction more often than not.  We'll use two CPUs that don't talk to each other as well as one would expect, squandering the extra processing power (this is a late addition to the design to have parity with the competition, admittedly).  Finally, we're going to pack the controller with unnecessary buttons in places that make them almost painful to press.  Sounds like this console is destined for success, right?  Don't be so dismissive.  Atari, Nintendo, and Sega have made these mistakes over the years along with other familiar names like Mattel and Microsoft.  Journey through the hall of "What they hell were they thinking?!" in this article at Technologizer about Fifteen Classic Game Console Design Mistakes.

The Sega Saturn contained two main CPUs, two graphics processors, and five other supporting microprocessors. This unconventionally large array of chips made the Saturn significantly complex to program for game developers (especially compared to the much simpler PlayStation) and more expensive to manufacture for Sega.

Chief among the hardware difficulties was the fact that the two main CPUs had trouble accessing the system memory at the same time. This situation often left one CPU waiting for the other to finish its task before beginning its own instructions, nullifying many advantages gained by having two processors in the first place.

Another complication of the Saturn’s design showed up later in the product’s life span. Throughout the commercial run of any game system, manufacturers typically find ways to reduce the complexity of their console’s hardware design, thus trimming production costs and allowing for lower retail prices. Unfortunately for Sega, the Saturn’s complex architecture made simplifying the hardware difficult, vastly reducing Sega’s ability to remain price competitive (and profitable) as the 32-bit generation rolled along.

All of your favorite baffling design decisions are here, from the 10NES lockout chip in the original Nintendo Entertainment System to the Atari 5200's painfully outdated sound chip to the Virtual Boy's reliance on the color red.  Plenty of consoles have their weaknesses, but these tend to be the more boneheaded choices that probably seemed like smart moves at the time.

(via Vintage Computing and Gaming)