Why was this a surprise
Fantastic device, but typical UK academia. Why were they surprised?
They are selling a powerful development board at a price that undercuts EVERYONE.
At that price point even professional developers will buy a handful of them to use in lab equipment etc. Even bigger companies will use them for test equipment as internal development costs are so high, etc. etc.
Not to mention, there are millions of geeks out there for whom $35 is small change and they will want one even if it ends up in a drawer, having been hardly used.
Similarly, the price point is so low that it is within the 'throwaway' bracket. I.e. it can be bought by the curious, with no significant risk, even if they never use it.
I think they have done a great job, but I am old enough to remember the supply problems in the early 80s home computer revolution. This caused some manufacturers to go bust when they eventually oversupplied but the technology had by that time moved on.
Lets hope that the 6 years development time of the original is not reflected in follow on products.