I sort of wanted one at work. I have a Thunderbolt (2.0) hub, that has thunderbolt in, with thunderbolt, gigabit ethernet, usb 3.0, audio, mini display port, and hdmi out. The hope was that one cable was all I would need to plug in whenever I dock my laptop at work, which has two monitors. Turns out that the only way to get two monitors with fed from one thunderbolt cable is if one monitor takes thunderbolt directly. So while one thunderbolt cable can do one 4K monitor, it can't do two 1920 monitors. Oh well, at least it's only two cables I have to plug in.
This was disappointing for me, as well, though I knew it before I bought my Thunderbolt dock. I'm pretty sure you could technically make it work with only one cable in the laptop if you bought another Thunderbolt dock and plugged it in to your existing Thunderbolt dock, but I didn't want to spend twice as much money as the already expensive dock cost. (Every once in a while, I'll think about replacing my dual displays with a single larger one of 27" or more, but I'm still not sure about that.)