"A very inexpensive microphone offering two distinct, non-overlapping upgrade paths."
The dual USB/XLR connection means it works out-of-the-box with your PC via USB, and can later be plugged into a separate audio interface (not included) via an XLR cable for a potential audio quality upgrade.
This is for the beginner streamer or podcaster who wants the lowest possible initial cost with a clear, built-in upgrade path. It makes sense if you plan to buy an audio interface later, but not right now.
Anyone who already owns an audio interface can get a better-sounding dedicated XLR microphone for a similar price. Users wanting a simple, higher-quality plug-and-play USB mic should look at models that don't compromise their budget to include XLR components.