I suspect that may also be somewhat responsible for the demise of the XServe. Nobody wants to pay a premium for a glitzy machine that spends it's life in a dark room.
The XServe got rave reviews from admins. It was very well designed, easy to do anything without tools (that wasn't as common when the XServe was introduced). And compared to Windows servers, the licensing made them much less expensive.
You keep your server room dark when you're in there? Do you keep night vision goggles in the man trap? I like walking into the server room and seeing all those nice Sun systems racked up, or the cool looks of the EMC and NetApp racks, rather than the ugly hodgepodge of the x86 server racks. It makes the server room look neater, and I'm a server neat freak (channel and label that cabling!). I'm not alone in this.