It did not flop. It performed exactly as expected.
I think you're wrong there, they took a big swing with a lot of marketing and a lot of big oem's putting out designs and then it went nowhere. Dev kit? Delayed for about two months, and recalled and cancelled not more than two months after release. Software compatibility though improved is still a crapshow.
Microsoft finally put out a windows on arm image, which again doesn't seem to be going anywhere. There's a lot of work towards making things work and be compatible that no one seems to be willing to make. It doesn't seem like ARM will supplant x86 any time soon