Why not use this? First it is new for many, and produced in China, so many will trust more brand cells like Samsung, LG and so on.
Second it is 13A max continuous discharge, that is like 6.5A discharge for a 18650 cell. For big engines that is not enough, it could be enough for big packs used with relatively small engines.
Reasons to use this cell - 1# price lower than brand 18650 cells, 2# longer life, 3# less problems with temperatures. As usually price is most important issue for growing sales, so in the end this cell could be a good choice for popular ebikes, for models like the project "with Vector copy" that was able to pass the big Kickstarter test. And by the way, those are not copy frames, the real producer of the frames is not in Germany.