As a blind person myself, I think I get from where you're coming here. But, as has been suggested by others, my first read of this was "non-native English speaker" rather than "offensive." I can't count how many times we've been referred to by folks as "blinds," which cracks me up every time (in a good-natured way, that is.) My girlfriend, a wheelchair user and speaker of 4 languages, regularly finds such things amusing as well, particularly as she can usually understand the linguistic reasoning behind much of the awkward phrasing.

That said, I'm glad they seem to be working with blind/visually-impaired folks. I hope they likewise staff their company with blind developers/designers as well, since we're still not terribly well-represented in tech, and it always makes me a little sad to see companies building products for us, but only involving us in the testing/final steps. I'd love to hack on something like this myself, and have played with Arduino-based echolocation augmentation for help with solo cycling/sports/other non-basic use cases. I hope there are blind developers working with you on the firmware.