[knackernews]

For those curious but don't have the time or desire to read 1294 words of fluff, the reason (which I got from another article) is to make buildings more accessible for the elderly, disabled and the arthritic. It's much easier to use a door lever than it is to twist a door knob.

[MattGrommes]

The entire article wasn't fluff. One thing it talked about was the idea that this specifically isn't "for the elderly", etc. It's to make it more accessible for everyone, which in turn helps the disabled.