I have a personal quibble: FireWire may be a dead product, but there are a lot of legacy devices out there (mostly in the audio world). The current-generation Thunderbolt–FireWire adapter is completely inadequate for these devices, for two reasons: 1) they’re an end-of-line device, meaning they don’t daisy chain, which makes them difficult to use with devices that have few TB ports and 2) they are limited by TB power delivery maximums to only 10W, which many FireWire legacy devices easily exceed when operating on bus power. As an example, I have a not-that-old FireWire audio interface that I’d like to run off bus power from my laptop, on the go. It draws 7.5W idle, but spikes over 10W during startup (charging capacitors, I’m sure). I can’t use it with the TB bus adapter, I need either DC power (dumb) or a second adapter (since like good FW devices this has two ports for daisy chaining). The DC power port went out a while back, so now I use an Original iPod FireWire charger on the second port to deliver enough power.
It would be nice if anyone offered a powered FireWire adapter that could deliver a lot of wattage for legacy devices.