...and how do you know a seamless fully functional continuum experience isn't a killer feature for the general public?
I just have a hard time believing the general public would be excited by the idea of running Win32 software (we won't have any meaningful continuum capable UWP apps for quite some time yet) from a phone sized package that still requires them to hook up a large monitor and keyboard. For most, that would surely seem like MS is just making things more complicated, compared to just using an ultrabook which already integrates all the required peripherals.
I think the reception so far is further evidence that not many people are genuinely excited by the prospects of Continuum.
Lastly, MS doesn't seem to think Continuum is of much interest to consumers either. They are marketing it towards enterprise customers.
While Continuum is certainly a unique feature, I just don't see the mass market being interested in that capability, particularly not while it remains essentially a desktop computer in a small package. That's really not compatible with mass market needs.
Ok, so what is a killer feature for you then,
A killer feature is any disruptive technology or feature. A disruptive techology or feature is one that revolutionizes the market to which the technology is introduced, or it creates an entirely new market that didn't previously exist.
When Apple released the first iPhone, it was the only pocketable device that allowed people to surf the web in a way that didn't make you want to kill yourself. That, combined with the touch interface made the iPhone uniquely useful and uniquely fool proof. It single handedly made smartphones a mass market phenomenon.
The introduction of the graphical user interface was also a killer feature.
There are a gazillion other examples but I'm sure you get the idea.