
To be clear, this is about defaults for user-created stuff, like Word files. Ultimately it proved to be a good decision, and anyway TNR is still usually the default for serif-specified text. Of course the switch from Times New Roman back in 2007 was controversial - going from a serif default to a sans serif default ruffled a lot of feathers.

A default font should be something you don’t notice and don’t feel the need to change unless you want something specific.

You probably don’t think much about Calibri, if you think about fonts at all, but that’s a good thing in this context. Microsoft’s default font for all its Office products (and built-in apps like WordPad) is on its way out and the company now needs your help picking a new one.
