Why so few PCI Express x1 Components?

I posted this in the Hardware section originally but then thought it might be an interesting article. PCIe has been around long enough you'd thinks mfg would have started development years ago. Video card mfg quickly adopted PCIe X16. As BUff pointed out in the original post, there are a few wireless cards now and Creative is talking about a PCIe sound card but overall PCIe development has really lagged. Given how quickly new tech standards are usually accepted, this seems really strange.