I'm less worried about the requirement for an internet connection than I am about the single point of failure. When the centralised service goes down, all your tags are useless squiggles.
Sure, but you have to admit that history is littered with things like this where they still died anyway. Can you not see how people could have concerns over this?
(I've commented elsewhere on this page BTW; I don't think the fact these are valid concerns makes it inherently bad ...)