More like Xiaomi is a weird word to Western ears and eyes, while FitBit is intuitive to pronounce and its rhyming is pleasant to the ears.
Marketing 101: Pick a name for your product that's easy for your customers.
As for Xiaomi, they are quite frequent on pages of trendy journals there and there with sponsored articles, yet if you ask an average reader if they even noticed it, most will say no.
There are innumerable examples of Japanese companies that changed their names to make them easier to market. Panasonic, for example.
More recently out of Korea, look at the rebranding of Lucky Goldstar as simply "LG." Worked wonders.
There are plenty of Chinese brands that are successful in the West. But they are always brands that are appealing to the Western ear. Vizio. Element. TCL. All better names than "Xiaomi."
Or this comment is an example of blaming bad marketing on racism..
Because it is a Chinese company, and thus, it is "uncool"
I think this is another exemplary case of Chinese company with a superior product being greatly weighted down by its "Chineseness" in Western markets.