Ok, so its an unlikely scenario, but having someone as big as MS do this will set the trend for web based authentication of everything. How many small companies are going to follow this lead, forcing regular security checks down the throats of customers on the basis that it is an "Industry Standard" way of doing things. And how many of those are going to go bust in a year or two, leaving customers up s**t creak with no method of propulsion?
The problem with any tech is that it's nearly impossible to make it perfect. In some situations like airbags, you can make the system very simple and independent, so it's not prone to failure.
Airbags aren't perfect. I know that for sure as i blew the side impact bag in a VW when a tyre popped. How do you think the car knows whether to deploy an airbag? A lateral g sensor, or in more advanced systems there may be sensors in the doors/pillars. Its still electronics that can go wrong.
Programmers used to batch environments may find it hard to live without giant listings; we would find it hard to use them. -- D.M. Ritchie